CHAPTER FOUR

‘This isn’t going to be enough though,’ Bex pointed out, holding the net of electrodes she’d ‘liberated’.

It was the morning of the next day, and they were all sitting around the lounge of the apartment that Bex had rented. Kieron and Sam were still enthused by the success of their covert mission to get the EEG brainwave electrodes, while Bradley was just looking wiped out by the exertion.

Kieron glanced over at her. ‘It’s a standard head-size – one size fits all.’

‘That’s not what I meant. You’ve got the medical-standard electrodes for placing on the scalp. That’s great – but it’s just a prop. Just set-dressing. You can’t go into a high-tech corporation with a prop in your hand and an idea in your head. You need more than that.’

Kieron frowned, while Sam said, ‘Like what?’

‘OK – explain your idea to me again, slowly enough that someone not brought up with YouTube can understand it. Then I’ll tell you what else we need.’

Kieron leaned forward. ‘Sound is a wave, right? Just a pressure wave travelling through the air. Sounds you hear are caused by the increases and decreases of pressure against your eardrum.’

‘With you so far.’

‘Imagine those pressure waves on a graph, like mountains and valleys.’

She nodded. ‘Keep going.’

‘Now imagine that you can play another sound that’s the exact opposite of that graph – wherever there’s a mountain on one, there’s a valley on the other. And vice versa.’

‘They would cancel out,’ Bex said, picturing it in her head. ‘There would be no landscape – sorry, noise – at all. Everything would be flat.’

‘Correct.’ Kieron looked as if he was going to continue, but Sam jumped in.

‘Brainwaves are like sound waves, except that they are caused by positive and negative electrical currents rather than the physical movement of air molecules. If you look at a graph of your brainwaves they look just like sound waves. The maths is the same.’

‘So,’ Bex said, following the thought process along, ‘if you can find a way to project a brainwave into a brain that’s opposite to the brainwave it’s already experiencing, the two will cancel out. That’s your theory? It has the benefit of simplicity, I suppose.’

Kieron nodded. ‘That’s it,’ he said hurriedly, before Sam could interject again. ‘The question is – how do you get the new brainwave into the brain?’

‘And also,’ Bradley murmured from where he was slumped, eyes half closed, ‘how do you know you’ll switch the brain off temporarily rather than permanently?’

‘Yeah, I’ve been thinking about that.’

Bex had to admire Kieron’s acting skills. She suspected he wasn’t anywhere near as confident as his tone suggested.

He explained his theory. ‘We’re not stopping the brain producing the brainwaves – we’re just cancelling them out after they’re produced. Going back to the sound-wave analogy, the tuba is still playing, it’s just that you can’t hear the music.’

‘I hate tubas,’ Bradley said quietly. Bex wasn’t sure if he was telling the truth, making a joke or losing his grip on events. He straightened himself up a bit and went on: ‘When you say you’re cancelling out the brainwaves, does that include the signals that tell the heart to keep beating or the lungs to inflate and deflate?’

Bex relaxed. Bradley still knew what was happening.

‘We’re not saying it’ll work,’ Sam pointed out. ‘We’re just saying it has to sound as if it could.’

‘And besides,’ Kieron added, ‘we’ve been researching this. We really have. The brain produces a whole complicated set of brainwaves – alpha waves, beta waves, gamma waves, delta waves, and probably others as well. Some of them are associated with conscious thought – those are the alpha waves. Some are more associated with autonomic bodily functions like heartbeat and breathing. Those are, like, the delta waves and stuff. We aren’t planning to cancel them all out – just the ones that are linked to conscious thought.’

‘“And stuff”,’ Bradley said, settling back with his eyes closed again. ‘I like the tech-talk. It’s very reassuring.’

‘We’re not planning on cancelling any of them out,’ Sam reminded them all again. ‘We’re just saying that we can do it.’ He pointed to the hairnet of electrodes that Bex held. ‘That’s the microphone and the loudspeaker combined, if you like. We’re saying we can use that to record the waves that the brain is producing and then play them back but reversed.’

Bex tried to picture it. ‘So – you fire a net like this over someone’s head, then feed signals into it. Sounds complicated.’

‘I’ve actually put together a flash animation of it in action,’ Kieron said. ‘It looks good.’

‘I’m sure it does.’ She thought for a minute. Sam tried to say something, but she held up her hand to stop him. ‘OK – the problem as I see it is this: you’ve got your prop, and you’ve got your flash animation. That’s enough to get you through the Goldfinch Institute’s door. That’s the lure, if you like. It attracts the fish. But look at it from the fish’s point of view. Once it gets close to the lure and realises there’s actually no worm there, it’ll swim off. What’s your worm?’

Sam just looked confused. ‘I don’t understand,’ he said.

Kieron was keeping up though. He nodded slowly. ‘You mean, if we just dangle the idea in front of them, they can say, “Cool idea, lads,” then pat us on the head, send us away and use the idea themselves. We need to have something that they can’t develop – at least, not in a hurry. Something they need us for.’

Bex nodded. ‘You need a worm.’

Kieron and Sam swapped glances. Bex was impressed by the way they seemed to almost share the same thoughts sometimes. They didn’t need to talk – they just each knew what the other one was thinking. That was a close friendship.

‘We need –’ Kieron started to say.

‘– some kind of mathematical simulation of brainwaves,’ Sam continued.

‘One that’s connected to a simulated heart, respiratory system and so on,’ Kieron went on.

‘That way –’

Kieron again, continuing rather than interrupting: ‘– we can show that transmitting a reversed brainwave will cancel out the top-level brain functions while allowing the lower level ones to keep going.’

‘We need a simulated person,’ they chorused together.

‘Correct.’ Bex didn’t know if it was correct or not, but it sounded convincing. ‘So how do you get one?’

The two boys just stared at each other.

‘Neural network?’ Sam queried.

Kieron nodded. ‘Something like that. Let me check.’ He slipped the ARCC glasses back on and started to wave his hands around, accessing information from the ether.

Bex glanced over at Bradley. ‘How are you doing, Brad?’

‘Hanging on,’ he said, eyes still closed. ‘I get little peaks of energy, and then it all seems to fade away for a while.’

‘Hopefully the doctor will be able to sort that out.’ Bex tried to sound less worried than she actually was.

‘When’s she coming?’

Bex winced. ‘Unfortunately I think it’ll be after the three of us have left for America. Will you be all right to let her in?’

Bradley smiled. ‘Maybe I’ll invite Courtney over. She can let her in.’

Bex was about to say that she didn’t want any strangers in the flat when she realised that this doctor who was coming to see Bradley was technically a stranger and Courtney wasn’t. Before she could resolve the logical discontinuity in her mind, Bradley went on:

‘Did you get in contact with SIS-TERR? Have you accepted the new mission?’

She nodded but then, realising that Bradley’s eyes were closed, said, ‘Yes – I sent them a message. Just a simple acknowledgement.’

‘And what about our last job – the one in Mumbai? What did you tell them about that?’

Bex frowned. ‘That was trickier. Obviously I couldn’t admit what had really happened – Blood and Soil stealing the briefcase, me going after it, discovering that there were five neutron bombs set to explode across the Middle East and Pakistan, joining up with a multi-billionaire to locate the devices and then relying on two teenagers to block the signal that would launch them. I mean, that would just be stupid. Even if they did believe me – and frankly I barely believe it myself – they’d drop us like a hot potato.’ She sighed. ‘In the end I went back to the simple fact that my brief was to witness the handover of the case containing the information on where the last neutron bomb was located. I told them I watched it being handed over to two Westerners with close-cut blond hair. That’s the truth, pretty much. They don’t need to know about anything that happened after that.’

‘Just so I know,’ Bradley said. ‘I didn’t want to contradict you, if asked.’

Bex noticed that Kieron looked as if he wanted to say something. ‘What is it, Kieron?’

‘There’s a researcher at Newcastle University who’s doing research on the brain/body interface,’ he said. ‘He’s trying to work out whether self-awareness is an inevitable result of linking a brain and a body up, or whether it’s something else.’

‘Self-awareness?’ Bradley asked.

It was Sam who answered. ‘Dogs are self-aware,’ he pointed out. ‘You put a dog in front of a mirror and it knows that the image is a reflection of itself, not another dog. You put a cat in front of a mirror and it thinks it’s looking at another cat. Dogs are self-aware, as are elephants and dolphins. Cats aren’t.’

‘And people get paid to research this kind of thing?’ Bex was impressed. ‘We’re in the wrong game!’

‘Anyway,’ Kieron went on, ‘this bloke’s developed a simulated brain that produces brainwaves just like a real brain does. He intends to connect it to various mechanical arms and sensors, like cameras, to see if it develops a sense of self. That’s what we need to take with us – the simulation. We can demonstrate it to this Todd guy at the Institute.’ A frown crossed his face. ‘There’s one problem though. The research is being sponsored by the Ministry of Defence. They’re hoping to develop ways of commanding aircraft and tanks using brainwaves rather than hands-on controls or remote control. The lab is separate from the rest of the university, and it’s in a high-security environment. We’re going to have trouble getting in there and taking his simulation.’ He shrugged. ‘On the other hand, that does mean it’s something the Goldfinch Institute won’t have access to.’ He smiled. ‘It’s a worm that nobody else is using to fish with.’

‘That’s not the only problem you’ll have,’ Bradley pointed out. He raised a hand and tapped his head. ‘What if this simulated brain is actually a real brain – a real intelligence? Isn’t that going to complicate things?’

‘It’s not,’ Kieron said dismissively. ‘It’s a replica – like a synthesiser making an artificial noise that sounds like a tuba. It’s not a real tuba, and it never will be. It’s just a representation of one.’ He looked over at Sam. ‘That’s right, isn’t it?’

‘I hate tubas,’ Bradley said quietly. ‘Did I mention.’

‘And we’re not planning on taking this researcher’s entire work, are we?’ Bex asked, ignoring him. ‘I mean, this mission is important and all, but I’d hate to destroy a man’s career.’

Kieron shook his head. ‘We’ll just take a copy. It’s several terabytes of code, but I’ve got a portable hard drive that’ll take it.’

Bex sighed. ‘So – having just stolen one thing from a hospital, you now want to steal something else from a military research laboratory. You kids don’t do anything by halves, do you? Where is this place?’

‘About half an hour’s drive away.’

Bex closed her eyes briefly. This was all getting far too complicated. ‘And it’s on a military base?’

‘No – it’s on university grounds, but the laboratory itself has alarms and security systems.’

‘Then what’s your plan for getting in and stealing this data?’ she asked.

Kieron winced. ‘That depends,’ he said. ‘Can we use your credit card?’

Kieron’s plan involved driving out to a nearby electronics store. When Bex saw what he wanted to buy – a small drone with five propellers and a high-definition camera, operated by a remote control – she almost refused.

‘This isn’t Christmas!’ she said, trying to keep her voice down so that she didn’t attract any attention from the store clerk on the till. ‘I’m not buying you toys!’

‘Oh,’ Kieron said, ignoring her as he kept on going down the aisle, ‘I’ll need a wireless USB transmitter as well. And we may as well get a 5TB portable hard drive. It’ll save me having to go home.’ He looked a little shamefaced. ‘Anyway, mine’s filled up with PDFs of comics I’ve downloaded. I don’t want to have to delete them.’

A thought struck Bex. She glanced at the store clerk, then said, ‘Hang on a second – why can’t we access this researcher’s computer with the ARCC kit and download the whole thing that way? It’ll save the trouble of having to break in to a secure facility.’

Kieron shook his head. ‘Two reasons. Firstly, because it’s technically an MoD computer, it’s stand-alone – not connected to any networks or anything, to avoid being hacked by the Chinese or the Russians. I can’t use the ARCC kit to get into it. Secondly, the bandwidth of the ARCC isn’t big enough to scoop up several terabytes of data in a hurry anyway. Even if I could connect up remotely, it would take hours to siphon off the data, and anything could happen in that time. The researcher might discover that we’ve linked in, some kind of alarm might trip, the computer might power down or even crash – anything. I can use the ARCC stuff to get past any password he might be using, or any encryption, but after that it’s like trying to fit a swimming pool’s worth of data into a bucket.’

‘Hence –’ Bex indicated his shopping basket.

Kieron shook his head. ‘Exactly.’

Sam came around a corner and joined them. Spotting the drone, he said, ‘Ooh – nice!’

‘What’s that behind your back?’ Bex asked suspiciously, noticing the way he was standing oddly.

‘Behind my – oh, this!’ He brought his hand into sight. He was holding a box.

‘What’s that?’ Bex asked.

‘It’s a game capture card,’ Kieron said when Sam didn’t answer. ‘You use it for recording computer games you’re playing so you can upload them to YouTube for people to watch.’

‘And that’s a thing, is it?’ Bex shook her head. ‘The latest in spectator sports – kids watching other kids playing computer games rather than playing the games themselves. It’s even lazier than watching football rather than playing it!’

Kieron and Sam looked at each other in what to her looked suspiciously like pity. ‘You wouldn’t understand,’ they said together. Under his breath Sam added, ‘And why would anyone want to watch football?’

From the electronics store they drove directly to the university site. Kieron had thrown a rapid battery charger into the basket, and he used it to power the drone up while Bex drove.

The university was on a campus away from Newcastle, almost out in the countryside. It was largely open, and Bex drove cautiously around the ring road that encompassed it, waiting for Kieron to tell her where to stop. Students were everywhere – groups of them, couples holding hands and individuals rushing to get to lectures.

Bex glanced sideways at Kieron. He was watching the students with a wistful expression.

‘Ever thought about going to college?’ she asked quietly.

‘I’ve thought about it,’ he admitted, ‘but I’ve got to get through my GCSEs first. And I don’t know what I want to study.’ He shrugged. ‘And even if I did know what to study, I’m not sure whether I could take the lifestyle. I’m not, you know, the most sociable of people. I prefer my own company, and that of just a few friends.’ He jerked a thumb towards the back seat. ‘Like him.’

‘Maybe Sam would go to college as well. And even if he doesn’t, there’ll be other people like you there – people who have –’ she had been going to say ‘social anxiety issues’, but stopped herself at the last moment. It sounded too clinical, too harsh – ‘a few really good friends, rather than a lot of casual acquaintances,’ she finished lamely.

‘Maybe.’ He shrugged and looked away.

Bex wasn’t sure whether to press him further, but before she could say anything he pointed out of the window. ‘Down there,’ he said, indicating a side road that led away from the university campus.

A few minutes later they found themselves at a car park with about half the slots occupied. An automated barrier separated the car park from the road, but it was raised and she drove straight through without any problems. She parked in a large enough space that she wasn’t near any other cars, and was also shielded by a couple of trees.

Beyond a wire fence at the far side of the car park was a single-storey building. On top of the fence, coils of wire lined with razor-sharp spikes caught the light. Looking along the fence, Bex saw an entrance turnstile with a security-card reader. There was a camera pointed at the turnstile, presumably to record anyone going in or out.

‘Are you ready?’ Bex asked Kieron.

‘Ready,’ he confirmed. ‘If you can just lower the window.’

She did so, and he held the drone outside. ‘Sam – ready?’

‘I am,’ Sam confirmed. Immediately the drone started to lift off, leaving Kieron’s hands and rising up into the air. Beneath it Kieron had attached the portable hard drive, using cable ties. He’d also adapted a long plastic strut from the drone’s packaging to hold the drive’s USB cable out ahead of it, like a lance. Or a stinger, maybe.

‘You’re not assuming that someone is going to let that thing in through the front door?’ she asked. Actually, she’d already worked out what he was going to do – or, at least, what she would do under the same conditions – but she wanted to check that he’d thought it all through.

‘It’s warm today,’ Kieron said, watching as Sam moved the drone through the air, keeping it low and in the shadow of as many trees and shrubs as he could manage. ‘The windows are open. You can see them. We should be able to get the drone in through the lab window.’

Bex frowned. As the drone hopped up, over the fence and down again, into the cover of some large green wheelie bins, she said, ‘But if the window’s open, the researcher could be inside. He’ll see the drone the minute it comes in.’

‘We’ve thought of that too,’ Kieron said.

He reached back, over his shoulder. ‘Give me the tablet.’

Sam passed over the tablet, which was controlling the drone, and on which the image from its HD camera was being shown, then opened his door and slipped out. Keeping low, he moved towards some cars that were parked over near the fence.

‘Have you ever noticed,’ Kieron said, distracted slightly by steering the drone around a corner, relying on the moving image from the camera to show him where to go, ‘that whenever your car alarm goes off, you know it’s your alarm and not anybody else’s? Even Courtney, four floors up in her flat, can apparently tell her own car alarm from anyone else’s. And she can get down those stairs in thirty seconds flat as well, before any thief has a chance to get away.’ He smiled. ‘Sam says he’s seen her chasing car thieves down the road, chucking stones at them until they’re out of reach.’

Outside, Sam had reached a particular parked car. He looked around, making sure nobody was watching, then reached down and picked up a thick branch that had dropped off the tree he was standing beneath. Bracing himself, he bought the branch back over his shoulder like an American baseball player preparing to hit a ball, then swished it rapidly forward. The branch smacked into the car’s radiator grille. The peace and quiet of the car park suddenly vanished, replaced by the shrill electronic blast of the car’s alarm. Sam edged back into the shadow of the tree, dropping the branch as he did so, then slipped back along the line of bushes to where Bex was parked.

‘Give it a few minutes,’ he said as he got back inside.

‘That is the right car, isn’t it?’ Bex asked.

‘According to the information I found on the researcher,’ Kieron said, ‘it’s his car. For sure.’

‘Let’s just hope he hasn’t sold it to a work colleague in the past few days.’

Kieron grinned. ‘It’s still his alarm,’ he pointed out. ‘He won’t have forgotten it. Coming out to check will be like an automatic reaction.’ He grew distant. ‘My mum said that she could always tell when I was crying, even at nursery when there were maybe twenty or thirty babies there. If she turned up to get me and heard crying, she’d know if it was me.’ The expression vanished from his face, replaced by excitement. ‘Look – there he is!’

Indeed, a man in corduroy trousers and an open-necked shirt was running down the path that linked the research building with the security gate on the fence. He scrabbled in his pocket for his keys.

‘We are go,’ Kieron said, stroking his fingers across the tablet.

On the screen, Bex saw the image change. The drone had been hovering low, beneath an open window, but now it was rising. As far as the camera could see, the room inside was empty. Kieron guided the drone carefully inside. Bex could see several large computers, as well as whiteboards covered with diagrams and equations and a bookcase filled with books and journals and files crammed full of papers.

The researcher had got through the security turnstile now. He turned the alarm off, using his key fob, and glanced around suspiciously.

Kieron manoeuvred the drone towards one of the computers.

‘How do you know it’s that one?’ Bex asked.

‘His jacket is on the back of the chair.’ Kieron guided the drone towards the computer. The USB cable, projecting into the camera’s picture from above, wavered slightly as the drone moved, but it headed for an empty USB port on the computer. ‘And,’ he added, ‘it’s the only one switched on.’

‘How are you going to actually find the file?’ Bex asked. ‘I mean, you can hardly operate the keyboard with that drone, no matter how good you are.’

‘Don’t need to,’ Sam said from behind them. ‘The portable drive has an automatic back-up function. Makes it easy for people who aren’t computer experts, like we are. You plug it in, and it hoovers up everything it can find.’ He sniffed. ‘I configured it on the drive here.’

On the screen, the USB plug edged forward as Kieron manipulated the drone’s controls. It took a few attempts, but eventually he got the two of them touching.

‘Now,’ he said, ‘let’s hope those propellers can generate enough force to push it in.’

‘And then pull it out again,’ Sam observed. ‘Don’t forget that bit.’

In the car park, the researcher was now checking over his car, looking for any damage or broken windows.

‘Got it!’ Kieron exclaimed as the USB plug slid into the computer’s port. ‘I can’t see whether the drive is actually backing up. Let’s hope you configured it correctly.’

‘Worry about your own side of things,’ Sam grumbled. ‘I did my job properly.’

‘How long do you think the transfer will take?’ Kieron asked.

Sam thought for a moment. ‘Less than a minute,’ he said.

With a last glance around, the researcher locked his car again and headed towards the security turnstile.

‘I’ve just thought of something,’ Sam said. It sounded as if he was trying to keep his voice light and casual.

‘What’s that?’ Kieron asked.

‘We won’t actually know when the transfer has ended.’

Kieron swore. ‘You said it’ll take a minute! “Less than a minute,” you said!’

‘Hey, that was an estimate. I could be wrong!’

‘Well, what happens if we disengage too early?’

Sam shrugged. ‘Depends. We might end up with some of the files but not all of them. Or the drive might get corrupted.’

The researcher was through the security turnstile now, and had nearly got to the building. As he reached the door it opened and a man in a security guard’s uniform emerged to hold it open for him. They exchanged a few words before the researcher went inside.

‘I’m going to stop it now,’ Kieron said.

‘Wait!’ Sam’s tone was strident. ‘Just give it a few more seconds!’

Kieron’s fingers hovered over the tablet’s surface. He was obviously torn between doing what he thought was best and what Sam was saying.

‘Just a little longer!’ Sam urged.

Bex shook her head abruptly. ‘Get out now. If he gets back to his lab and sees the drone, we’re done for.’

Kieron nodded. He touched the tablet’s screen, commanding the drone to disengage. The camera display showed it pulling back, tugging the USB cable out without problem and revealing more and more of the computer and the laboratory as it retreated.

Alarms suddenly blared out from the building inside the wire fence.

Bex started the car.

Kieron drew a wide circle on the tablet screen. The drone rotated, showing a blurred view of the bookcases and the whiteboards before it stabilised with its camera pointed at the door.

The researcher stood in the doorway. His face was set in stunned, disbelieving lines, but his hand rested on an alarm box set beside the door frame.

‘We’re getting out of here,’ Bex said, feeling the sudden pulse of adrenalin rushing through her bloodstream like wildfire. Her heart rate sped up, and she felt suddenly nauseous. The feeling passed quickly, as it always did. She threw the gears into reverse, put her foot on the accelerator and raised the clutch until the engine caught. The car moved smoothly backwards.

She glanced at the building. As she watched, the door swung open and several uniformed guards rushed out. They looked around uncertainly. One of them saw the car and shouted. Bex couldn’t hear what he was saying, but his intention was clear. He wanted them to stop.

She glanced down at the tablet in Kieron’s hands as she automatically put the car into first gear and started to accelerate away from their secluded parking slot in a curve that would take them towards the barrier. From what she could see in her hurried look, Kieron had successfully steered the drone through the open window. She could see blue sky, and a flat asphalt roof.

She turned back to check the barrier.

Which was coming down rapidly.

Her foot went down instinctively and she slammed the car into a higher gear. The car leaped forward, pressing Kieron back into the seat. From behind her, Bex heard Sam’s muffled curse as, caught by surprise, he banged his head on the back of his seat.

The barrier was halfway down now – a thick black diagonal line drawn across the bright blue sky. In the rear-view mirror she saw the security guards running to intercept them. They’d triggered some emergency setting that had caused the turnstile to swing completely open.

The car was halfway out of the car park when the barrier crashed down onto its roof. The screech of metal on metal set Bex’s teeth on edge, like biting down on a piece of tin foil. The car juddered, hesitated, then sprang ahead, skidding out onto the road in a curve that left smoking black rubber on the tarmac behind them.

‘Slow down!’ Kieron shouted.

‘I will not slow down!’ she shouted back. ‘Why would you even think that?’

‘Because of the drone!’ he yelled.

Bex looked sideways. The drone was halfway between the building and them. Its USB cable had come loose from the cable-ties and was hanging down, waving in the wind generated by its flight.

‘Sam,’ Bex ordered, ‘open your window. Kieron, steer that thing towards us. I’ll go as slowly as I can, but I’m not going to risk getting caught. The guards will be phoning ahead – we need to get out of here, fast.’

She drove as slowly as she dared. If the security guards hadn’t memorised their licence plate, and if she could lose them among a whole load of traffic on a major road, then they might just get away. They could ditch the car later as it would certainly have been caught on camera. For now they just needed to concentrate on getting away.

The drone hovered alongside them. It was going as fast as it could, and it wavered unsteadily.

‘Bring it in through the window,’ Sam shouted.

‘I can’t!’ Kieron shouted back, panic edging his voice. ‘If I try to steer it sideways I’ll lose speed, and it’s going as fast as it can just to keep up with us.’

Bex heard Sam’s exasperated sigh above the noise of the engine and the wind whistling in through the open window. She felt him scrambling around in the back seat. She glanced in her driver’s side mirror to see if anyone was following them. For a second she saw a clear road, but then the view was obscured by Sam’s head and chest. He was climbing out of the rear window!

‘What the hell are you doing?’ she called.

‘What I have to!’ he called back. He had one arm inside the car, hanging on, while he perched on the edge of the open window. Reaching up with his free hand, he grabbed hold of the hovering drone.

‘Cut the motors,’ he shouted to Kieron. ‘I’ve got it!’

Moments later he had pulled himself back inside, triumphantly holding the drone. Two of the propellers had been knocked off as he manoeuvred it through the gap, but the all-important removable hard drive still hung underneath it.

‘Can we please,’ Sam said breathlessly, ‘never do that again?’