If there was a right side to the A23, then Streatham Hill lay on it and Tulse Hill on the other. Whilst the former could boast famous former residents such as James Bond actor Sir Roger Moore, the latter's former residents tended to be more infamous than famous, and to serve their time at Her Majesty's pleasure. If they were lucky, it would at least be nearby in either Brixton or Wandsworth prison, where friends and family could visit more easily.

It had been a hard day at the office for Dr How; it always is for members of any intelligent species who have to answer to a Dolt. He'd left his Spectrel to figure out the identity of his hacker, and when he'd checked in at lunch it had given him a name, a location and a background. One thing the Doctor had learnt was that action should be as swift and decisive as possible. He used his work computer to access his Spectrel, and used it to perform a hack of his own.

The address was only a mile or so from his home, and getting within walking distance merely involved taking a different bus up from Brixton Tube station. Distance was a strange concept in London compared with anywhere else, even for someone as well-travelled as Dr How. The neighbourhood on one side of a road could be radically different from that on the other. In east London he'd seen slum housing next to bankers' apartments, as if the physical world had been Photoshopped by a political satirist.

The A23 headed due south to the coast, and was nicknamed the Brighton Road after the city at its southern terminus. The A205 – the South Circular – went directly east-west. Streatham Hill lay to the south-west of the crossroads, and Tulse Hill to the north-west. They were polar opposites. If the Luftwaffe had had a plan to destroy Tulse Hill in the Second World War, and to sap the morale of its inhabitants by making their lives a misery, then they had failed utterly in their mission. Unfortunately, the plan had been taken up in the Sixties by enthusiastic young urban planners, and had succeeded on a scale that would have delighted Hitler.

When he'd invested in Du Cane Court in Balham as it was being built in the Depression of the Thirties, the Doctor had known it was a winning prospect. It had overground rail services to Victoria, Clapham Junction and London Bridge. The newly-extended Northern Line connected it with just about anywhere else in London you'd want to go. Designed as easy living for the well-off, Du Cane Court had filled with minor West End stars, who could get home from a show in twenty minutes. Streatham Hill, then the 'West End of South London' was just four minutes away by overground rail. Although Tulse Hill did have an overground station, it was not much used by residents and therefore not much used at all; there being no reason to visit the area.

He got off the bus and walked up the hill to the squat, brutalist five-storey block of flats. His sense of being watched didn't come from the CCTV cameras perched on custom-built poles and masked within mirrored protective globes. The cameras were probably more of a disincentive, rather than a true deterrent.

His bespoke black suit and white shirt were his everyday wear and his uniform. And, like a uniform, it was a signal to whoever was watching him that he wasn't afraid of being noticed, of being different. His business attire showed that he meant business.

There had been a long and successful campaign against anti-social behaviour by the local council. One part of this was the CCTV; the other increased physical security. The stairwell had been secured with a steel gate against entry by drug-users looking for somewhere dry and private to take a hit.

He walked up to the entryphone and took out a little oblong object the size of a pocket knife, with a surface of brushed metal. He swept it over the keypad and heard the buzzing as a solenoid pulled back the bolt. He pushed open the gate and went through. The eyes were curious now – warier. But he sensed they were turning to another subject of interest. He took the stairs up to the third storey and looked at the door of number thirty-eight. The dark blue paint indicated that it was not privately owned. On this type of estate, the doors of the tenants who'd opted to buy at a discount were generally fancier. He'd not noticed any in this development, and it was little wonder. He rang the bell.

The footsteps were heavy, and the door was answered by a plump Afro-Caribbean woman in her forties. Her clothes were cheap but smart. "It's Kevin again, innit?" she said, before he could utter a word. "I swear I will disown that boy one day."

"Is he in?"

"Nah, he's out with his mates. Well, he's out. Whether they're his mates or not is another matter. He's had his dinner so probably won't be back soon." She paused. "I hope it's not serious. Mind if I see some ID?"

"My card, Mrs Thomson. Here."

Mrs Thomson examined his card. "What does someone from the Technology Transmission Department at Imperial College want with my son? Anyway, I need to see photo ID. Sorry."

"Certainly. My driving licence."

She examined the Doctor's licence but kept his business card. "Good enough. Won't you come in, Dr How?" She put his card on the mantelpiece, next to a wedding picture of what he assumed was Mrs Thomson and her husband – an older white man with black-framed glasses. "Tea?"

"No, thank you. I wasn't planning to stay long."

"Come." She took a seat on a black leather armchair and motioned him to a place on the matching sofa. "I take it you're not about to offer him a position as an associate professor?" She let out a cackle and slapped a substantial thigh, which wobbled.

He smiled. "Unfortunately not, although I don't doubt that your son is smart enough."

"Reeaaaally?" she said. "I just wish I could direct that brain of his into something more productive. Like so many young ones, he's not got the focus. Lord knows I've tried to make him knuckle down. ADHD I think it is. I see it a lot up at the hospital. I work in A&E. The younger ones, they just don't have the patience to sit quietly. Can't read a book or a magazine. Always fiddling with their phones."

"As I said, he's certainly smart enough to be able to hack into a pretty secure environment."

"Oh, no. Not that again. I told him it's dangerous. You hack into the American systems now and they extradite you and put you away for decades. I can't afford no fancy lawyer. It's him and his conspiracy theories, you know. UFOs and all that nonsense. I mean, I always tell him that if aliens were so smart, why in the name of God would they bother with us? Eh?" She shook her head.

"I suppose it's at least stopped him from getting into other sorts of trouble. His record says he was cautioned for a few petty offences – shoplifting and the like."

"Ah, you know about that. That was enough for him. He's fairly legit now – computer repairs, phone unlocking, that sort of thing. Works out of his bedroom." She flicked her head in the direction of a hallway.

"Yes, I know exactly the sort of thing. Password resets on stolen PCs and iPads. Unlocking smartphones."

"What can I do, Dr How? It gets him a modicum of respect on the estate. He's like his dear departed father – smart, but not the kind of man who can stand up to other men. Not physically, at least. But he has a good heart, I promise you. Maybe one day he'll set up a proper shop down in Brixton. I always hoped someone would take him as an apprentice at one of those places in the arcade, or Brixton Village."

"It would certainly be a good use of his talents, Mrs Thomson. It's been nice talking with you, but I have to get on."

"Would you like me to get him to write you a letter of apology, Doctor?"

"Heavens, no. Just tell him that if he tries that stunt again he'll find his hard disc reformatted. He has quite a collection of programs on it, so he knows how many days it'll take to download and reinstall them. Tell him I mentioned that. Oh, and tell him I'm not bluffing. I wiped out his high score on Bioshock." It wasn't all that had happened to Kevin's computer. He wasn't sure whether Kevin knew just how much trouble he might be in.

"Serves him right, Doctor. I'll let him know. You take care on the way out. Do you know where you're going?" She rose to let him out.

It was dark outside, and the night was overcast and moonless. The streetlights on the estate were of the mercury-vapour variety used for industrial parks, giving a stark white light with a hint of pink.

"It's not much of a walk home from here."

"Best stick to the main road, though. Bye-bye, Doctor. And thank you for not being too hard on the boy."

He trotted down the concrete stairs, footsteps echoing around and out of the stairwell. He pressed the green exit button, the gate buzzed, and he was out onto the tarmac.

There was a route round the back of the block, and that was his fastest way to the South Circular, and home. Attention wasn't on him, but he was very interested in seeing who it was on now as he walked stealthily towards the service area at the rear of the flats. He stopped at the corner of the building and listened.

"I told you, I know nothing," said one voice.

"Jesus, Kevin. The Feds knew exactly who and what they was lookin' for. They went straight into Joe's and nicked him. His brother says they even quoted the serial number of his laptop at him, and it matched. Boom – straight in the van, no arguments."

"Spyware," said another voice. "Shopped him. You said that machine was clean when you was done with it."

"I swear it was clean," said Kevin.

"You got careless. Know what happens when fruit gets handled carelessly, Kevin?" said the first voice.

"It gets bruised," said the other. There was the sound of scuffling, then the noise of a body being bounced off something large and hollow.

"I don't know nothing," said Kevin.

"How comes you got a nice friendly visit from the Feds ten minutes ago, eh? Giving you a reward from Crimestoppers, was they?"

"On my life, I don't know who that was. It can't have been a Fed. You saw him – he wasn't wearing a stab-proof vest, was he?"

"So if he wasn't a Fed, who was he? Went straight through the gate."

Dr How stepped out from behind the corner. "It's easy if you have one of these," he said, and held up the oblong metal object.

Kevin's two interrogators had him pushed up against one of several giant dumpsters. They loosened their grip. All three stared at the suited man.

"Whoa, it's the Feds," said the larger of the two assailants.

"Good evening, officer," said the other. "We was just having a quiet word with young Mister Thomson here."

"I assume you've finished now, gentlemen?"

"Who's asking?" said a much deeper voice. A chunky youth stepped out of the shadows. "My Dad always told me to ask for ID. No warrant card, no conversation."

"Consider me just another one of Kevin's customers who wants a word," said the Doctor.

"Who are you?" asked the chunky youth. "You're on my turf. You ain't got no visa and you ain't paid no entry fee. Know what I'm sayin'?"

"Do excuse me. I thought this was public property. I didn't realise you were King of the Dumpsters."

Chunky's companions knew better than to laugh. Kevin's eyes opened in terror. There was a snick as a blade opened in Chunky's right hand. It glinted as the youth pointed it at Dr How's face.

"Just a word of advice, mate," said one of the youths holding Kevin. "Now would be a good time to show some serious respect."

"Yeah, and like maybe say your prayers if you don't," said the other. Kevin was pushed back against a dumpster and all three advanced on the Doctor.

"Kevin," called the Doctor, "I want you to look away now."

"No need," said Chunky. "He didn't see nothin'. Did you, Kev?"

"Nothing, I swear," said Kevin.

"Cover your eyes, Kevin," ordered the Doctor. He raised the metal object above his head. Its brushed metal casing reflected the light in a diffuse, unthreatening way. The trio's eyes followed it.

"Wh –" Chunky managed, before a blinding flash lit up the service area.

"Come, Kevin," said the Doctor. He pocketed the object and walked past the youths, who were rubbing their eyes and crying in agony. Chunky stumbled into a dumpster and fell over, letting out a fresh scream as he fell on a broken bottle and cut his shin. The Doctor grabbed Kevin by the lapel of his anorak and pulled him to his feet.

"What have you done to them? We should get an ambulance. My Mum's a –"

"They'll be alright in a few minutes. Your he-man might do well to get a tetanus jab though." Still holding Kevin by the lapel, he marched him off along the narrow path that led to the South Circular.

"Oh, I get it. It's like in Men in Black! Cool, man!"

"No, not really. They'll be a bit confused as to what happened, but they'll just associate you with pain from now on. You're coming with me."

"Jesus, I can't believe it. You're like Agent K."

The Doctor swung Kevin round. "Get this into your dense little head, Kevin. Men in Black is fiction. What is fact, my friend, is that you are in serious trouble. Maybe more trouble than you could ever imagine."

"With who?"

"No, not with Who. With me. With How. And some other people. I don't know who."

"I don't understand."

"You understood enough to hack into my systems. Then you came knocking at my door. I'll be needing answers, Kevin." They reached the South Circular. The rush-hour had finished, but there was a steady stream of traffic as they turned and headed west.

"Now, you either come with me and give me some answers, or you go back home and face your mother's wrath. And I'll also trash your computer remotely."

"You'd have a job. I'm the best."

"Really? Guess who put the spyware on Joe's machine that got him nicked?"

"Well, it wasn't me."

"I know."

"So it was you?"

"No, it wasn't me. I don't know who or what it was, Kevin. And if I don't know who it was then if I were you I'd be very, very scared right now."

They reached the busy junction. Seeing a gap in the speeding traffic, the Doctor grabbed the youth's arm and forced him to run across the dual carriageway to the traffic island. They caught the last seconds of a green light on the other side. They were now heading south along the A23.

"But I don't understand."

"Never play a game you don't understand, Kevin. You broke someone's rules and you paid for it."

"What's the worst that could happen?"

"Oh, gosh, Kevin. What do you think the King of the Dumpsters was going to do to you after Joe's court case over the stolen laptop?"

"I could have talked my way out of it."

The Doctor stopped and turned to face the youth. "Really, Kevin. You might have found it a whole lot more difficult with no teeth."

"Look, it wasn't –"

The Doctor continued his brisk walk. "Just suppose – I don't know how good you are with hypothetical questions, Kevin –– but just suppose whoever did that to Joe's laptop – I say 'Joe's' laptop, but of course it's stolen –- just suppose they did that to every single machine you've hacked in the last two months."

"They couldn't. Could they?"

"Oh yes, they could, Kevin. And can you just imagine how unpopular that would make you in your manor? Yes, I can hear your little brain working like mad now. Part of you's thinking that things might be quite a bit easier with the boys in the slammer. But it's not a full flush, is it? And then they do get to come out in a few months. Not so much fun then. Not so easy to talk your way out if it, is it?"

"Jesus. How do you know all this?"

"Because I did you a bit of a favour, sunshine. I stopped it from happening. I'll show you everything when we get back to my place, which – as you know –– is but a short distance away."

"I'm not going in that house with that mad dog of yours. He'll kill me."

"He's a she. Still, we'd better make sure you get off on the right foot with her. Here, let's get her a tin of dog food."

They ducked into a small independent grocer's. The Doctor scanned the tins. "Hmm. Rabbit. I think she'd go for that. I remember her catching something small, cute and furry once. Trouble was, it only looked cute. Pure evil, it was." He declined a plastic bag. "She prefers things raw, and I rather suspect this is cooked. Still, it's the thought that counts, isn't it?"

They crossed the dual carriageway, then headed down the leafy road which led into Telford Park Estate. The noise of the traffic quickly died behind them. A couple of hundred yards later they were at Dr How's front door. "I'm not quite sure whether she's expecting you," he said as he unlocked it. "She can be a bit funny with strangers, so you'd better leave the introductions to me. But I'm sure she'll like you. Eventually."

Kevin crept warily into the porch behind the Doctor, who closed the front door behind him. He clicked the timer switch and the UV light came on. "If you'll just raise your arms, that would be great."

"What's this?" Kevin noticed his white shoelaces glowing.

"UV light. Kills bacteria. Can't be too careful. You'll find I can be a bit fastidious where hygiene is concerned. Get used to it." He opened the door to the rest of the house and they went in.

"Trini," called the Doctor. "We've got company." There was no response.

Kevin screamed and grabbed the door handle, unable to turn it in his panic.

"What is it?" asked the Doctor. The youth was now in petrified shock, his back to the door. The Doctor pushed him away from the exit, out into the hallway. A huge spider covered in short jet-black fur, its head the size of a bowling ball and a body twice the size, was dangling on the end of a single sliver of silk, its legs spread out three feet on either side for balance. Its eight green eyes were locked into Kevin's, less than two feet from his face. Its mandibles twitched. Kevin let out a small choking noise.

"What's the matter, Kevin? Have you got arachnophobia?"

Kevin choked back a gurgle.

"Oh, Trini. You're not hypnotising him, are you? I'm so sorry, Kevin. It's one of their hunting strategies in the wild for larger kills. She doesn't get much of a chance to practise it these days, but even so, it's a bit rude. After all, she's not intending to kill you. Not that I know, anyway."

"C-c-c-c. S-s-s-st –"

"Can I stop her? Yes, of course. Trinity, would you please let Kevin go?"

The spider rose silently on her silken sliver and, with a flick of her body, stood upside-down on the ceiling, eyes still fixed on Kevin.

"Come on, let him go." Trinity backed off to a point in the ceiling just above where the stairs began. "Oh, very well." He turned to Kevin. "She wants to show off. It's her favourite party trick. Watch this."

The Doctor went up to the third step. Trinity dangled a hind leg. The Doctor jumped up and grabbed it, as if it were a trapeze bar. She held that leg steady whilst she crawled back to her previous position in the middle of the hall ceiling. "Pretty impressive, isn't she? Capable of holding over a hundred times her own bodyweight."

Trinity dabbed the spinner in her rear on the ceiling and spun out a fresh sliver, returning the Doctor gently to the floor. She flashed back up to the ceiling on the silk, then dropped to the floor without a line, landing silently on her feet in front of Kevin. She backed off a few feet, to the end of the corridor next to the stairs.

"Now, she's said hello to you. It's only good manners that you say hello to her."

"H-h-h-h-h. T-t-t-t-t-t. Ht."

The Doctor shook Kevin by the shoulders and waved his hands in front of his eyes. "Come on, snap out of it. She's not going to bite you, lad."

"H-h-h-hello, T-Trinity," said Kevin.

"I thought the cat had got your tongue there, Kevin." The Doctor looked down at his guest's jeans. "At least you've not wet yourself."

If a spider could have laughed, it would have looked like Trinity did at that moment – her head nodding and mandibles twitching.

"In the wild, with larger prey, they hypnotise them first, you see. Bit like a snake does. Then the next thing you know, you're dead. Or probably you don't know at all, because you're dead, come to think of it. Whilst she's got you fixed with her two big eyes, the others are busy working out the physiological details – what sort of sensory systems you've got, how good they are, muscles, central nervous system, circulatory system – you know; veins, arteries, that sort of thing. Then she'd probably either paralyse you or just slash an artery. Or, if you're smaller, chop your head clean off. If your head's the important bit, that is. Normally the case, but you just never know, do you? Well, she does. Obviously. Or at least, she does if you make the mistake of giving her a few seconds to work it out. Are you better now?"

"She's not a dog. She's a spider."

"And they say science education is on the decline in this country. Well, not exactly a spider, but near enough. Let's just call her the most efficient predator I've ever met. She's not from round these parts, you know."

The Doctor turned to address Trinity. "Kevin's actually very thoughtful. He insisted we stop and buy you a can of this." He held up the tin of dog food. Trinity's attention switched to the can, and he handed it to Kevin. Her attention stayed on the can.

"G-good girl," said Kevin. "I hope you like rabbit?"

Trinity's rear legs straightened with a twitch that made Kevin start.

"I'd take that as a yes, Kevin. Now, how about you just give her the food? She's in feeding mode now, and you don't want to leave her in that state without giving her something. Quickly."

"Do you have a tin-opener?"

"I hardly think that will be necessary, Kevin."

The youth turned, open-mouthed, to the Doctor.

"She likes a bit of activity with her feeding. Look, if you're still a little scared why don't you just throw it to her?"

"But –"

"Oh, for heaven's sake. You're not going to hurt her. She likes to play with her food. She's a predator, for God's sake. Don't you get it?"

Kevin lobbed the tin underarm in Trinity's direction. It wobbled in its arc, but the spider reached out a front leg and caught it noiselessly in a paw. She set it down in front of her the right way up.

"She's not going to...?"

"No, she doesn't eat metal. A bit of bone, yes, but metal? No. Be sensible."

"What's she doing?"

"Reading the label, of course. What do you expect?"

Trinity grasped the tin with one leg and slid it under her mandibles. There was a pop, and then a tearing noise. She rotated the can in increments, each marked by the sound of metal tearing. The top fell off, hit the floor and rang for a couple of seconds as it settled down. Trinity gulped down the contents with her mandibles. Once the bulk was finished she tore the can at the sides and cleaned out the last morsels of food.

"Wow," said Kevin, as Trinity scuttled off in the direction of the kitchen, carrying the ripped tin and its lid in her mandibles.

"Yes. She does make your native species look a bit – I don't want to be unfair here – a bit underdeveloped, doesn't she?"

From the kitchen came the sound of a tin being rinsed and then thrown into a recycling bin.

"Y-yes. Does she attack humans? Is she the dog I heard?"

"Everything attacks humans. Bacteria, viruses, insects, dogs, mice, fish. Anything will attack a human if you annoy it enough. And, unfortunately, humans seem to specialise in being annoying. I put it down to your curiosity. And your blind ignorance too, I suppose. Of course, you mostly don't mean any harm – but you never seem to get the message, do you? I often wonder if, as a species, you're autistic. Or maybe a touch too arrogant for your own good."

"You mean you're –"

"Not human? No."

"What are you, then?"

"I brought you here to answer a few questions of my own. The answers to yours will become abundantly clear over time. But right now, for your sake, you have to answer mine. Those are the rules for now."

An oversized black cat with green eyes padded into the hall from the direction of the kitchen. It purred and rubbed itself against Kevin's legs. He bent down and stroked its head, and it pushed back into his hand.

"Are you, like, not afraid that Trinity's going to eat your cat?"

"Trinity is the cat."

Trinity opened her jaws and gave a large meowl. Kevin whipped his hand away.

"I think she likes you," said the Doctor. "And not as a foodstuff, either. That's a relief. Particularly for you, I suspect."

 

The Doctor had insisted Kevin wash his hands thoroughly in anti-bacterial soap in the downstairs bathroom, then given him a cup of hot chocolate for the shock he'd suffered.

"I think I recognise some of the artists you have on your wall," said Kevin, as they descended the stairs to the cellar. He'd never met someone this well-to-do; nor had he been in a house like this one – not as an invited guest, at least – and was struggling for conversation. "Those kinds of prints can be very expensive, can't they?"

"Prints? Those are originals."

"But I swear I saw a something like an Old Master, and maybe a – what's-his-name? – a van Gogh. Something in that style, anyway."

"Oh, Vincent spent a few years just down the road in Brixton. Surely you knew that? His uncle got him a job at Goupil and Cie, the art dealers, who then transferred him to their place on the Strand. Walked to work every day. He was happy here, for a time. Such a shame when Eugénie rejected him. He'd done the odd sketch, so I told him it would be good therapy – take his mind off things. We kept in touch. I sent him some woollen colour swatches after he moved to Arles, and he sent me that portrait back in return. I was mortified – poor chap was on his uppers by then. I sent him enough rent money for a quarter. Probably blew it on absinthe. You can't meddle too much in the lives of others."

"He sent you a portrait of you?"

"Of course. Very much the done thing in those days. Right, if you'll sit here for me, please." The Doctor pulled up a second chair in front of a large oak desk. The only item on it was a laptop.

Kevin sat down and looked around the bare, white room with its flagstone floor. He was glad Trinity hadn't joined them. "What's the phone box for?" There was a traditional red British telephone box in the corner of the room opposite to where they'd come in. It was in pristine condition. The red paint seemed to pulse with the deepness of its red, and the glass panes reflected the white walls so brightly he couldn't see inside.

"Can you just concentrate and stop asking questions?"

Kevin swung his chair round to look at the screen of the laptop.

The Doctor adopted a sober tone. "Look, we need to get to the bottom of this. You tried to hack me, but you also tried to hack someone else. They didn't like it one iota, and they were going to make you pay for it. Now, I need to know who it was. Clear?"

"But why should you care?"

"Because they also hacked me. I know who you are, but I don't know who they are. No offence, but I think they are a considerably greater threat to me than you are. Now, think back to what you were doing."

"Well, you know, I was just, like, surfing some stuff on the dark web, you know."

"Come on, hurry up. How did you come across me and my system?"

"Oh, I could see there was all this activity. An IP address somewhere in Dagenham. Something looked a bit odd."

"What?"

"I've never seen code like it before. People have styles. It just seemed... I dunno. Alien."

"Go on."

"Well the characters wasn't even recognised by my system. You know, the characters wasn't supported by any font I could find."

"Not even something that supported Ancient Greek, Cyrillic script, Arabic, Thai, something like that?"

"Nah, nothing. I parsed it in all these fonts and it was all just nonsense."

"And so you did what?"

"Chopped it into binary and started crunching."

"And?"

"And it still didn't make much sense. Then I realised a big chunk of it could be turned the other way and used as graphics."

"Turned the other way? What do you mean?"

"I sorted it into blocks. There was a repeating bit of code. Did I mention that?"

"No; a critical detail you missed out. Never mind. Go on."

"It was a map."

"Of?"

"I don't know. I only got part of it."

"But you saved it?" Kevin nodded. "We'll look at it later. Now, that was the passive thing you were doing. What was the active thing that made them hit back?"

"They were snooping around an IP address in Streatham Hill, using the Dagenham thing as a proxy. I mean, what's something of that kind of industrial strength interested in something around my 'hood for?" He saw the Doctor wince at the thought of being considered in the same neighbourhood as himself. "Well, we's all south of the River, innit? No one loves us."

The Doctor sighed. "You're right. North Londoners will never get it. Keep going."

"So I hacked them trying to hack you. So it wasn't really that I was hacking you indiscriminately, or anything. I was kinda hacking them hacking you."

"Hack not, lest ye be hacked."

"Sorry?"

"Go on, Kevin. Go on."

"And your system was using the same sort of code, except that I couldn't convert it to graphics or nothing."

"At that stage, neither my system nor theirs would have been using graphics."

"And then I realised that the whole reason I could see any of this in the first place was that they'd been using the Dagenham address as a proxy but using me as a masking IP all along. I was on the inside, if you see what I mean."

"Which is why I couldn't see their IP address."

"And that's it. End of story. Next thing I know, I'm shut down. So what do you reckon?"

There was silence for a few seconds, whilst the Doctor thought. "I have a cousin in Dagenham," he said. "I do hope he's alright. You see, this," he indicated to his laptop, "is an antique."

"No it's not, it's a tasty bit of kit, that."

"Kevin. It's an antique. Well, okay, it's not an antique. Technically an antique has to be at least a hundred years old. But what I mean is that it's really primitive. This is to my sort of computing what flint axes are to a machine gun."

"Nah, you don't know –"

"Take it from me, lad. It's Stone Age. I just use it as a convenient interface. Now, what could be better than to hide behind a curious young man who's interested in conspiracy theories, and happens to live within walking distance? Let's have a look at your map, shall we?"

"It's on my computer back at home."

"The entire contents of which I have here."

"That's theft!"

"Kevin, another little saying for you: He who lives by the sword, dies by the sword. You were lucky to have intercepted the graphics because the rest of it would have been gobbledegook to you. Or anyone else, for that matter. Here we are." An image resolved itself on the screen.

"Yeah, that's it. It's a map. Not like any map I've seen."

"That's because it's a geological map, Kevin. Let me just fiddle with a few of these files." The Doctor ran a secondary program. "There you are. A 3D map of... of the geology of an area of Essex."

"What's all them coloured layers?"

"Those are rock strata. See, on the top there, is what's called the alluvial layer. That's the soil and clay laid down at the end of the last Ice Age. Underneath that you've got successive layers of older formations, from the blue clay through which the Tube system is built, down to sandstone, shale, and what have you."

"So why's someone looking at that?"

"You want to map it to see if there are valuable minerals down there. Coal, for example, or oil. In this instance, the data seem to have been stolen from a company which was interested in shale deposits."

"Like shale gas."

"Oh, you do watch the news. Good man."

"I don't get it. Someone who's interested in shale gas is interested in hacking you."

"A couple of obvious things here, Kevin. First, you might notice a small dotted area of some complexity if I zoom in... like so."

"Yeah, gotcha. Looks like plans for something underground."

"Exactly. We don't know what, though. The second thing is that when you try to hack someone like me you're generally not merely interested in hacking."

"I was."

"Yes, well you're just insatiably curious. If you hack someone like me you're interested in neutralising me."

"What makes you say that?"

"Because whoever did it had already hacked my cousin. They were using his machine."

"You mean your cousin has a computer like a machine-gun too?"

"If we're sticking with that analogy, yes."

"You recognise the code?"

"Yes, it's Gaelfrey."

"Gallifrey? You're Dr Who, innit?"

"No. I'm not Dr Who. I'm Dr How. And it's not Gallifrey." The Doctor's tone switched in an instant from patient to irritated. "I don't want to hear that word in this house. Or anywhere around me. Understood?"

"Jesus, Doc. Sorry, man. Like, I didn't realise you was so sensitive."

"Sorry. I overreacted. You weren't to know."

Kevin twisted awkwardly on his seat. "Look, I need you to level with me. You're like... You're like the Doctor, innit? And that." He pointed at the phone box. "That thing over there is like the TARDIS."

Doctor How sighed deeply. "Yes, and no. I am a Doctor. There is no the Doctor, except in fiction. And except in one person's head in particular." He spat out the last sentence with some bitterness, but regained his composure. "Despite my assertion to the contrary, you think I'm Dr Who, don't you? A real-life Time Lord?"

"Yeah, man. It's like way cool."

"No, Kevin, it is not way cool. It is not even – as you mistakenly say in your street patois – like way cool. It is an enormous responsibility. A huge burden. Yes, a pleasure at some times, and it does occasionally have its privileges. It serves well my taste for art, for example. But most of the time it is bloody hard work. Do you understand me?"

"Like don't have a cow. I was just asking."

"Forget everything you know – or think you know – about Dr Who and Time Lords. It's a fiction. Do you understand?" Kevin nodded. "It's a fiction taken up unwittingly by the BBC, touted by a megalomaniac back in the Sixties. He's made my job a dozen times more difficult, and nearly trashed the entire universe into the bargain."

"So is that your –"

"No, it's not my TARDIS, Kevin! That's a misnomer."

"A...?"

"A misnomer." Kevin looked at him blankly. "It means wrong name. It's a misnomer put out by the BBC. TARDIS is actually a very rude word in my native language and nearly one in yours if you changed the 'a' for a 'u'. A certain someone, who will remain nameless, thought it would be terribly amusing. According to the BBC, TARDIS is supposed to mean Time And Relative Dimension In Space." The Doctor was now ranting wildly. "Can you believe the sheer gall of these people? Like they actually know, like they understand how the physics works?" The Doctor glared at Kevin, who shook his head.

"Let me tell you what it's like. It's like a troop of monkeys – and I mean monkeys, like baboons; not chimpanzees, not even apes – coming up to your very sophisticated saloon car with individual climate-control for each passenger, and a hi-fi system that would fool a bat. As you drive your state-of-the-art car through a safari park this troop of purple-bottomed baboons comes up to your car and calls it "Oog". And then – and then –– then, they have the cheek to first of all capitalise the entire thing, so it's not Tardis, it's T-A-R-D-I-S, just to spell out the first letters of exactly what these monkeys think the physics is that they can't even begin to comprehend. And after that they march down to another baboon who calls himself a lawyer and they register it as a trademark. So if I wanted to write my own biography, my autobiography, and I wanted the boneheaded human reader to understand the concept by way of using the word TARDIS, some baboon with a Technicolor™ bottom specialising in intellectual property law could demand money with menaces through the good courts of baboon society. And all this," spluttered the Doctor. "And all this after I saved your – forgive my crude colloquialism here – after I have saved your sorry collective Technicolor™ asses on more occasions than I care to remember."

Silence hung in the air. The Doctor was breathing deeply.

"And was that thing you used...?"

"No. It's not a Sonic Screwdriver. Such a thing does not exist. How in God's name could it? How could you possibly have something working on sound waves in the vacuum of space?" The Doctor slammed his fist on the desk.

"You has like got issues, hasn't you?"

The Doctor slowly closed his eyes, then reopened them. "Yes," he said quietly, "I have issues. I have issues about this and many other things. First of all, it's Gaelfrey. A script-editor misheard it and renamed it Gallifrey, probably because it didn't sound quite right for use on early evening Saturday television. Second, it's not a TARDIS, it's a Spectrel. That stands for Space Expanding-Contracting Time Relationship. I only use a capital for the first letter, because I consider it a proper noun, and no longer an acronym. I only call it that because it sounds nice in your language and gives you a set of words you can easily remember. It doesn't actually explain the physics any better than the word TARDIS, but I find that if I don't at least attempt a fancy name that sounds like a vaguely convincing – albeit absurd and nonsensical – explanation, then you humans don't trust it. Third, it is a Tsk Army Ultraknife. I will explain some other time just how idiotic it would be to call something so sophisticated a Sonic Screwdriver. Clear?"

"Yes, clear, boss."

"Boss?"

"Just a turn of phrase. Respect, innit?"

"Now, as it happens, fate has thrown us together. I recognised your thumbprint on the back of one of my Turners upstairs."

"What do you mean?"

"I mean your thumbprint is on the back of one of the pieces given to me by the painter J. M. W. Turner."

"How –"

"My system scanned your prints and matched them. Oh, don't worry about the damage. It's history. And I was reconciled to it long ago."

"But I never touched your Turner! How could I have?"

"That's quite literally another story, Kevin. You and I have to get through this one first."

"You mean...?"

"Yes, you're my new assistant and it looks like we're destined to have a series of adventures together. Welcome aboard. Please, call me Doctor. We have work to do."

"Wow, this is so cool, man!"

"I keep telling you that it is not cool, Kevin. It is highly dangerous. Oh, and if you think you're going to wander around telling all and sundry about your new position, you're very much mistaken."

"But can I not tell my Mum?"

"I suppose she has a right to know something, yes. But be careful what you tell her."

"Hang on just a second. Have you, like, had assistants before, yeah?"

"A few, yes."

"So, like, where are they now?"

"Dead, mostly."

"Dead?"

"You know, old age. For the most part."

Kevin goggled at him. "For the most part?"

"Yes, for the most part." The Doctor patted him on the shoulder. "Stick with me and do as I say and you should be okay. Before I forget, we'll start by giving you a couple of hundred quid for some new clothes. Here." He handed Kevin a wad of notes from his wallet. "For God's sake don't spend a penny of it on what you call bling. Clothes only, and I shall want to see itemised receipts. Understand me?"

"Yes, boss. Doctor."