The dream returned that night. I landed right in the middle of it, dropped into a dark corridor which I realised had to be deep in the cold bowels of the Museum. I heard a single set of slow, echoing footsteps behind me. It was pitch black and I had no chance of seeing whoever or whatever it was so, just like every other time, I ran. Up one corridor and down the next, bouncing off the walls in a blind, sweaty panic. I simply couldn’t shake off those relentless footsteps. The sound mingled with my own pounding pulse till I couldn’t tell which was which. Rounding the final bend, I just stopped myself from running smack into the gigantic head of a dragomansk. It was the size of a house and was illuminated by a sickly, garish green light. It stared at me curiously with its enormous compound eyes, turning its head slowly from side to side as though it didn’t know what to make of this tiny puppet-doll. Finding my voice at last, I screamed and woke myself up.

I didn’t know if I’d screamed in real life but if I had, at least I hadn’t woken Robeen. As I lay there trembling and working hard to steady my breathing I decided that, against orders, I would not be reporting the dream to Doc Carter. I wouldn’t report any of my dreams to him now, no matter how bad they got.

A couple of days later, time spent relocating to the new dig site on the coast, the four of us were called to Doc Carter’s room.

‘The fact is, we’re very interested in the particular projects you students have chosen,’ Doc Carter began. Multiple graphs on the holoscreen behind his shoulder winked and flashed as new data arrived and I tried to forget that it was all coming from the celephet on the back of my head. I tried to focus on what he was saying but it was hard.

‘Nisien, the initial designs you’ve made for modifying the amphibical are ingenious and we really want to see what becomes of them. It’s terrific that Robeen has agreed to team up with you on this potentially groundbreaking piece of work.’ Nisien beamed as though his birthdays had all come at once but Robeen merely nodded and kept her eyes on the floor. I didn’t get the feeling she was particularly interested in Nisien’s mechanical obsessions and I felt sorry for her. Didn’t she have a project of her own? At Pioneer School, Robeen was one of the superstar students, up for every award going, and it was hard to believe this was the same girl: a Robeen pushed into the background. I realised why she might hate me so much for all the extra attention I was getting.

‘As for you two…’ Doc Carter turned to Halley and myself, his eyes aglow. ‘Your respective Museum projects. Well, we’ve read your proposals and we’re sure they’ll add greatly to our appreciation of Earth’s natural and geological history, so well done.’

I’d feared my proposal might seem a little weak compared with the others but obviously I needn’t have worried. I didn’t know who he meant by ‘we’; who were the ones who read and considered the proposals? Probably members of the expeditionary party, Captain Calamus and maybe Core Panel back home. And Doc Carter, of course. He was right in the middle of all this decision-making.

‘Thanks,’ said Halley. There was a hard edge to his voice. If the Doctor noticed, he didn’t show it.

‘That’s why,’ each one of Doc Carter’s immaculate white teeth seemed to twinkle like a scale played on a keyboard and he flexed his fingers with glee, ‘for the first time ever, we’re suspending student archaeological duties. It’s more important you concentrate upon your very worthwhile projects. The class ones are at your disposal anytime, just remember the safety rules: visors down, alert signals on and sauroters at the ready. And of course if you’re outside, you must stay near cover at all times. Call for help anytime, that goes without saying. Nisien and Robeen, you’ll remain at Base to study the amphibicals so that shouldn’t be a problem.’

Poor Robeen, I thought again.

‘Is everyone happy with that?’ Doc Carter said.

‘You bet,’ said Nisien. Robeen said nothing and neither did Halley. I was happy, sort of. Happy to be returning to the Museum so soon. I’d convinced myself that the mysterious footsteps were something else, like creaks in the old building. I was keen to go back and begin dreaming about the rocks and fossils.

The morning was bright and for the first time, the sky was truly blue, a real marvel. The huge white puffy clouds high in the atmosphere barely seemed to move. If only I could have taken off my hood and visor and found a dry piece of ground to lie down and stare up at it. Outside the Base, Halley and I stood looking upwards for as long as we dared.

This time I drove, taking a similar route to our first outing. I guessed Halley wouldn’t protest if we took a detour via the Queen Street and arcade canals. I pulled the amphibical into shelter three times after alerts that dragomansk were about. The first two times, individual creatures came into view and didn’t stay long, but on the third we saw an enormous metamansk, the biggest we’d seen, weaving through the air, backwards and forwards, up and down, changing direction continually. I tried not to think about the dreadful pictures on the gallery walls.

‘Just look at them,’ I said. ‘They’re vile.’

‘Vile but … interesting. Fascinating. Look how they all move together so perfectly.’

‘Halley,’ I said. ‘You can’t mean it. You know they’d kill us if they knew we were here.’ But I could see he did mean it.

‘What do you think they eat?’

‘Small animals. Large animals.’ I hated even talking about them. ‘Did you see there’s no wildlife out in the open, except the water animals and the insects? The birds and mammals are all hiding in the woods and canals, where the dragomansk can’t reach.’

‘They must have been the deadliest of all the engineered insects, if the pictures on the Museum walls are accurate. Once they’d polished off the humans they must have started attacking one another in some kind of big insect war. The dragomansk came out on top.’

‘No wonder there’s so little left of Cardiff.’

‘No wonder we’re so keen to find a way to get rid of them.’ Halley changed the subject, perhaps because he could see I’d had enough. ‘At least we’re out here experiencing something. Imagine being Nisien, stuck back at Base. What a waste after coming all this way.’

‘He’s happy enough,’ I said. ‘Imagine being Robeen, stuck there helping him. She didn’t look happy, despite what Doc Carter said. She must be bored out of her mind.’

The metamansk broke up and once they were all out of sight, I edged our craft out of its hiding place and we set off again.

‘Don’t tell me you feel sorry for her, after the trouble she got you into?’

‘Trouble? What trouble? I was expecting a lot more than I got. Doc Carter practically ended up congratulating me. Sometimes I don’t like him. Don’t trust him anyway.’ I flinched as I said it, as though the celephet could transmit my thoughts straight to his computer. But of course, that was stupid.

‘You’re strange,’ Halley sighed. ‘Doc Carter’s nice to you so you don’t like him.’

‘But why’s he being so nice?’

‘It’s that celephet of yours. He’s pleased it’s working, that’s all. You’ve saved his whole experiment. How many times do I have to reassure you?’ Halley shook his head but his voice, even behind the visor, sounded strained.

‘Yes, but sometimes I get the feeling that’s not the whole story, about the celephet,’ I said. ‘You know, like you feel they’re not telling us everything about the dragomansk. Like there are these secrets they won’t trust us with. You said something like that the other day. Didn’t you, Halley?’

Halley said nothing.

The canals were just as beautiful as they’d been the first time and once more we ended up opening the roof and slipping back our visors and hoods. Our sauroters were primed and ready if the unthinkable happened and a dragomansk did appear, but that didn’t seem likely: the gaps between the trees were too narrow, and a thick mesh of hairy creepers hung from every branch, creepers we had to keep brushing out of the way to get anywhere. We saw more frogs, different kinds, and this time caught the flicker of larger creatures’ eyes, spying on us from the depths of dense vegetation. We saw more movement, the flash of limbs. I spotted something which might have been a very large domestic cat disappearing into the shadows behind a building. Maybe wildlife roamed the ruined buildings too. Halley seemed just as enchanted with our private watery garden as I was and we spent about an hour exploring before heading for the Museum.

I suppose Halley went straight upstairs to contemplate those stomach-turning pictures. He said he was combing the place for contemporary evidence: recordings, photographs or written accounts of what had happened in those dreadful last days. Me, I made a beeline for Origins of Earth, keen to explore but also hoping to begin a new poem.

So there I was, crouching in the darkness in the huge room, pouring over the ammonites and trilobites, as though I were fishing them up one by one from the bottom of the ocean. I daydreamed about warm, tropical seas full of such creatures and my awareness of my surroundings seemed to blur and drift away. In my imagination I was there, swimming amongst long-extinct animals in the tropical shallows, feeling the warmth of the sun filtering through the clear water on to my bare skin and knowing that when I surfaced, there it would be overhead, the bright, life-giving sun set in an enormous clear blue sky. It wasn’t like any place I could go to on Mars and as the sensual impressions swept over me I realised something for the first time: biologically I didn’t really belong on my home planet. It seemed obvious, but it hadn’t till then; the origin of my species was Earth. Earth, where I could breathe the air freely, Earth with its scary, out-of-control lushness and fecundity. It was on this mystifying, rich and diverse planet that I most longed to be.

The footsteps were indistinct at first. I tried my best to imagine they were something else, something expanding or contracting in the old building. They stopped and I was relieved, but they started again and there really was no mistaking them. In the room next door, someone was walking up and down, pacing a few steps then turning, pacing then turning. I could only see the door as a dark rectangle set in the dark wall, and at any moment I expected someone to appear.

I had felt fear before in my life, but not like this. I’d thought there couldn’t be anything scarier than being on board the Byd as itlaunched, when I was sure I was about to die. But the fear I felt alone in that room was very different. On Mars everything is known, everything is expected. This was entirely new, this primitive icy fear of the unknown. A real physical chill suffused my body and I couldn’t get up or shout out. I couldn’t do anything except stay kneeling where I was, following the sound of the footsteps as they paced this way and that on the other side of the wall. They sounded impatient, cross even, especially when they turned. Then as suddenly as they’d begun, the footsteps ceased.

The enchantment broken, I sprang to my feet. If the footsteps were Halley playing tricks, I would catch him this time. In my heart of hearts, I knew it wasn’t him. And if it wasn’t Halley and it wasn’t another member of the crew, who was it? Without stopping to get scared again, I ran to the door, turned the ancient ball handle and opened it, flashing my tilelight around the rectangular room. I had already known there wouldn’t be anyone there. But someone had been, I was sure.

I ran back into the hall and called Halley. The doors to the gallery wheezed open and he appeared on the landing, leaning over the balcony. We had a little chat, nothing important, and he returned to whatever he was doing. I went to sit amongst the statues. I don’t know why I didn’t tell him what had just happened.

I realised what the footsteps reminded me of: my dream, of course. They had been on the other side of a wall rather than chasing me down corridors but it took me a while to calm down before I could return to the fossil room. When I did, nothing happened; there were no more footsteps. I began to relax, pleased with myself for facing this strange new fear. Maybe it was the adrenalin rush but I was inspired to begin my poem:

Down amongst primitive fish

Curving their ways, discovering

New powers to dart and jab…

When Halley and I met for lunch, I still didn’t mention the footsteps. It seemed he’d forgotten all about them. I read him the start of my poem and he showed me some sketches he had made of the pictures upstairs. He told me he’d made staircases of books to view and copy the drawings higher up on the walls. Probably priceless books but they’d done the job. I found Halley’s copies almost as disturbing as the real pictures, but I swallowed my dislike and praised Halley’s technical ability. He had captured the gory scenes very well.

Of course, I would never have set foot in the common room if I’d realised Robeen and Nisien were having an argument, one of those horrible, whispered arguments designed to avoid attention.

‘All you had to do was hold the light steady!’ Nisien’s voice was hoarse and high-pitched with indignation. He saw me standing in the doorway. ‘Have a good day?’ he spluttered. ‘Because I haven’t. The afternoon’s been utterly wasted all because Robeen couldn’t keep her tilelight pointed in the right place and … and…’

‘…and he lasered through the wrong wires,’ Robeen finished his sentence for him. ‘It was nothing to do with me or the light. You just got it wrong, Nisien. Wrong, wrong, wrong.’

She knew exactly which buttons to press; this was the boy who couldn’t tolerate getting anything wrong.

‘You’ve been working on a real amphibical then?’ I said. ‘I didn’t realise your project was so advanced.’

‘We’ve been in the rotten service room all afternoon,’ said Robeen. ‘They’ve given him some useless decommissioned heap of rust to fiddle about with.’

‘Fiddle about with?’ His face turned very red. ‘No wonder you were acting so not-bothered, yawning and shaking your light about all over the place. I couldn’t concentrate. I couldn’t see what I was doing. Now I’ll have to trace those tiny wires back to their source and that could take days. I bet you did it on purpose, Robeen, you’re a very jealous girl. You know how absolutely vital my project is to this entire mission.’

‘No, it’s not.’

‘Well, all the missions to come then! You just can’t stand it that it’s my project that’s impressed everyone.’

‘Oh yes, your project. YOUR project.’ Robeen seemed close to tears.

I wanted to turn round and leave them to it, but I didn’t. I felt like consoling Robeen and maybe asking her if there wasn’t some project of her own she would rather do? Surely there was still time to submit an idea? Then I remembered what had happened the last time I’d tried being kind to Robeen.

As they continued their argument, it crossed my mind, not for the first time, how lucky Halley and I were to be spending all our time at the Museum. Nisien was incredibly bright and if he managed to make it work, his new amphibical device would be of tremendous benefit to future missions. I began to feel a little afraid: what were Halley and I actually doing at the Museum? Writing poems, drawing pictures? Nothing remotely scientific, that’s for sure. When Doc Carter came to realise how insignificant they were, would we find ourselves roped into Nisien’s project instead? I’d had an almighty fright at the Museum that morning but it was still where I wanted to be. If I could spend the rest of my time on Earth with Halley at the Museum and in the canals, that was all right by me. There were plenty of treasures still to be uncovered there, plenty of secrets to be revealed and dreams dreamed.

‘And you!’ Robeen rounded on me, trying to keep control of her tears. ‘Now I suppose you’re going to report us to your precious Doc Carter. You’ll enjoy that, won’t you?’

‘Of course not.’ I walked out of the room. Robeen really had no idea. She was obnoxious and Halley was right: I was some kind of idiot to feel a particle of sympathy for her.