The safe – apparently made from a steel alloy containing both tungsten and lutetium – was finally open and Jack and Dylan were examining the contents at the kitchen table.

  It was late Saturday afternoon and the light was fading. I stood by the window, watching a steady rainfall in the courtyard. The mews house was silent, apart from the occasional excited exclamation from Jack.

  ‘Look at this bit,’ he kept saying, and: ‘This is fantastic. Far more than I expected.’

  It had been a long and mostly silent journey home from Scotland. Dylan and I had grabbed a few, unsettled hours’ sleep at Edinburgh station, then caught an early-morning train back to London. We’d kept a lookout for Fergus – or the police – the whole time, but no one stopped or even approached us.

  ‘I don’t get it,’ Dylan had said. ‘Why hasn’t he come after us?’

  I thought about it. ‘Maybe he tried and Geri Paterson stopped him. Everyone says how powerful she is.’

  ‘Everyone’s right.’ Dylan looked away. ‘I met her months ago, when Jack found me. She flew out to Philadelphia to talk to me. I mean, Jack was great – he was my dad’s friend and I wanted to get to know him – but Geri just has this air about her – like whatever she wants, she gets. I was desperate to get away from my aunt anyway, but Geri made it sound like coming here would be the most exciting thing that would ever happen to me . . .’ She tailed off.

  I frowned. ‘How was visiting your relatives in London for two weeks and hanging out with Jack a few times going to be so exciting?’ I said.

  There was a long pause. ‘I can’t explain . . .’ Dylan hesitated.

  ‘Can’t explain what?’

  She shook her head. I stared at her, an uneasy feeling in the pit of my stomach. There was something Dylan wasn’t telling me. Something to do with Jack and Geri and the arrangement she’d made with them.

  Something to do with why she’d come to London.

  ‘So where do these relatives you’re staying with over here live?’ I asked.

  But Dylan closed her eyes and turned, pointedly, away from me.

  We didn’t speak much for the rest of the journey. Most of the time I laid my forehead against the cold train window and stared out at the changing landscape, while Dylan slept – or pretended to.

  As we travelled on, my thoughts drifted away from Dylan and whatever she was hiding from me back to Ketty and Ed. As I remembered their kiss, the reality of it gripped me like a claw, piercing through the numbness I’d felt earlier.

  The pain got worse and worse. Whatever I saw – fields, trees, houses – the only image on my brain was Ketty and Ed kissing. Even the sound the train made seemed to mock me.

  Ketty and Ed, went the engine. Ketty and Ed . . . Ketty and Ed.

  By the time we got to King’s Cross I was in such a state I couldn’t begin to lift the safe any more. Dylan had to get a porter with one of those flat trolleys to get it off the train. She threw me a few weird looks, but said nothing as the porter loaded us and the safe into a taxi.

  When we reached the mews houses, I’d recovered enough to teleport the safe inside, though I was scared I’d lose my focus at any moment.

  Jack didn’t seem to notice the mess I was in. He was there when we arrived – Dylan had phoned ahead to tell him everything – and full of praise for us both. A week ago I’d have lapped this up, but right now all I cared about was Ketty.

  What was she doing with a geek like Ed, anyway? I mean, Billy Martin had been bad enough. But what on earth did she see in Ed?

  I pressed my fingers against the French windows that led from the kitchen to the courtyard, tracing the outline of a raindrop that was trickling down the outside of the glass.

  ‘Come and see this, Nico.’ Jack’s insistent voice brought me back to the kitchen.

  I wandered over to the table. It was covered with the papers from inside the safe. There were masses of them . . . some typed, most handwritten. Loose pages had been shoved inside notebooks. I opened one at random. The handwriting was that old-fashioned sort with big loops hanging off every letter. The words were clear enough but the meaning was way beyond me. I scanned the page quickly, picking up only a few recognisable words: maternal . . . blood pressure . . . strand . . . in amongst all the bewildering jargon. The file kept referring to low molecular weight proteins and antigen processing genes. What on earth were they?

  ‘Not that, this.’ Jack pushed another notebook under my nose. It was typed. The open page was headed: Cobra. 07/08. Third recipient of Gene DR61-alpha. Processed: 08/Dec. Live birth 10.18 a.m., 07/August.

  Cobra. That was the code name Geri had told me I’d been given. And 07 August was my birth date. I read down the page. It was a list of dates – medical appointments by the look of it – with a record of blood pressure and temperature readings – plus a bunch of other medical data that I didn’t understand.

  I looked up at Jack. ‘This is all about me being implanted with the Medusa gene, isn’t it?’

  He nodded, all excited. ‘Yes, plus William’s record of his check-ups on your mother. Both William and Fergus Fox claimed William destroyed all this. It’s an amazing find.’

  ‘Great.’ I tried to summon up some enthusiasm. ‘So is the information on Viper here?’

  Jack’s face fell. ‘I haven’t found much about her identity yet, other than that she was female, which we already knew. At least I have a birth date for her now. That’s more than I had to go on when I was tracking Ed.’

  ‘What’s his code name?’ I asked, interested.

  ‘Sidewinder,’ said Jack. ‘It’s a kind of rattlesnake.’

  I nodded. That figured. Ed was a snake, too. Stealing my girl from under my nose.

  But even in the midst of my misery I knew that wasn’t fair. Ed had no idea how I felt about Ketty. In fact . . . with a jolt I remembered how I’d told him she liked him the evening we all went to the casino bar. He would probably never have had the confidence to talk to her if I hadn’t encouraged him. Which meant . . . oh my God . . .Ed and Ketty being together was my fault.

  ‘Hey, Jack.’ Dylan held up another dog-eared notebook. This one had an old-fashioned computer disk taped to the page. It was square and made of black plastic. Nothing like the CDs or mini-disks I was used to. Dylan peeled the disk off the notebook and turned it over.

  The word Medusa was written in red felt pen along the back. ‘D’you think this’ll have anything on it about Viper?’ Dylan asked, eagerly.

  Jack leaped up. ‘I’m going to try it in my old PC.’ He glanced down at the papers spread over the table. ‘Don’t move a thing.’ He rushed off.

  I wandered back to the window. The rain was still beating down outside – the only other sound was the low hum of the fridge in the corner.

  Dylan cleared her throat. ‘So, Nico . . . that girl in Fergus’s house . . . Ketty. Does she know how much you like her?’

  I turned round. Dylan was leaning back in her chair, head tilted to one side. As I stared at her, she raised her eyebrows.

  ‘Well?’

  I hesitated. I was so miserable that part of me was actually tempted to tell her the whole sad story. And yet that sardonic glint I’d seen before in Dylan’s eye made it impossible.

  ‘I don’t know what you’re talking about,’ I said evenly.

  Dylan rolled her eyes. ‘For God’s sake. I saw the way you looked at her yesterday. And you’ve been acting real lame ever since we left that house.’

  I shrugged and turned away again. A rustling of papers told me Dylan was, once again, looking at her dad’s notebooks.

  I don’t know how long I stood at the window. It was certainly at least half an hour before Jack reappeared. His mood had changed from excited to edgy. He paced round the kitchen as he spoke.

  ‘Okay, well the disk’s got the information we need. Er . . . unfortunately it looks like Viper will be harder to track down than I thought.’

  ‘Why?’ I asked.

  ‘I don’t have time to
explain,’ Jack said. ‘I’m taking the information to Geri now. Will you guys be okay till I get back?’

  Dylan stretched her arms and yawned, catlike. ‘Sure.’

  I looked up. ‘I think I’m going to go back home . . . to school . . .’

  Jack frowned. ‘Okay, if that’s what you want. But I’ll be back in a couple of hours. We could go out for a meal, later, the three of us?’

  I shook my head. Eating out with Jack in this edgy mood and Dylan casting me sly, knowing glances about Ketty was the last thing I wanted.

  Anyway, I’d been away over twenty-four hours, with my phone switched off that entire time. I was in enough trouble as it was . . . not only had I run away when I was supposed to be grounded, I’d also stolen those notes from Fergus’s safe.

  At least if I got back before Fergus returned, maybe I could talk my way out of the worst.

  ‘Er . . . sorry, but could you lend me a few quid for the tube?’ I said. ‘I used the last of my cash getting to the station to meet Dylan yesterday – and Fergus took away my Oyster card when he grounded me.’

  ‘Fine, I’ll leave some money for your journey back on the hall table,’ Jack said distractedly. ‘I’m going to dash, it’s going to be impossible getting a taxi at this hour. Just pull the door shut when you leave.’ He locked the Medusa papers away and rushed out.

  Seconds later Dylan called from the hall. ‘I’ve taken the cash on the table, but there’ll be more on Jack’s desk in his room.’

  ‘What? Wait . . .’

  But the front door slammed shut. Muttering to myself about Dylan muscling in on my cash, I gathered my stuff and went upstairs to Jack’s room. I hadn’t been in there before, but it was exactly as I’d expected – all pale wood furniture, and designer chairs. A couple of modern prints hung on the wall over the white-sheeted bed. No photos, though. In fact, no individual touches of any kind. It was more like a hotel room than someone’s personal space.

  I wandered over to the desk. It was the most cluttered area of the room, full of CDs and notebooks and scraps of paper – with a half-drunk mug of coffee in the corner. A pile of coins lay by the mug. I stared at it, wondering how much it would be okay for me to take. I reached out to pick up a couple of pound coins and some small change . . . and knocked the coffee mug over. It fell to the ground with a smash. Coffee splashed onto the wooden floor.

  Crap. I’d broken his mug.

  I bent over to pick up the pieces. As I leaned down, I noticed a little ledge under the desk. Something black was wedged inside. I peered closer, then pulled it out. It was the computer disk we’d just found – the one with Medusa written in red on the back.

  My heart skipped a beat. How come Jack had left it behind?

  I stared at the disk, the broken mug forgotten. If Jack turned up to his meeting with Geri without this he’d look really stupid. I grabbed a handful of coins off the pile and raced to the door. Jack had only been gone five minutes. He could easily still be on Long Acre, waiting for a cab. If I hurried, I should catch him.

  I caught sight of Jack at the corner of the street. He’d obviously given up on finding a cab and was disappearing into Covent Garden tube station. I pelted down the road and dived in after him. I had to buy a ticket and by the time I reached the lift, there was no sign of him. He must have already gone down. I got in the next lift.

  As I reached the platform, a westbound train pulled in. The doors slid open. I could see Jack right at the other end of the platform, stepping inside. I hesitated for a second then, as the doors beeped their about-to-close warning, I leaped into the nearest carriage.

  I tried to walk through the train, but the doors between the carriages were locked. I got out at the next station – Leicester Square – but I couldn’t see Jack on the platform. I nipped back on the train a few carriages along but I was still only halfway down when I saw Jack get off at the next station, Piccadilly Circus. He was right next to the way out and, again, had disappeared before I had time to call out his name.

  I followed him up the stairs but could see no sign of him at the ticket barrier. There were a number of exits out of the station – I darted up the nearest one. Surely I’d see him at surface level. I looked round. People everywhere. Yes. There he was, across the road from me, walking in the opposite direction.

  Fingering the disk in my pocket, I crossed the road and followed him. He was walking fast – too far ahead for me to catch him, or for him to hear my yells. He reached the bottom of the road and crossed into the park opposite. St James’s Park.

  I raced after him, worried I’d lose him in the trees. He hurried across the grass, finally stopping at a bridge overlooking a long stretch of water. Trees and bushes were planted on either bank and families of ducks swam up and down the stream.

  ‘Jack!’ I ran over.

  He jumped when he saw me. ‘Nico, what are you doing here?’

  I held out the black disk. ‘You forgot this.’

  Jack frowned. ‘Oh, right. Where did you find that?’

  I explained what had happened, feeling more than a little embarrassed. Jack maintained his frown throughout my story, looking edgily round every now and then.

  As I finished speaking he checked his watch. ‘Okay, you’re right, I’d have looked ridiculous without this. Er . . . You’d better get off.’ He took the disk and slipped it into his jacket pocket.

  Now it was my turn to frown. I hadn’t expected Jack to gush heartfelt thanks all over me, but I was saving his bacon here, for God’s sake. I’d thought at least he’d be grateful.

  ‘Okay.’ I slunk off. As I reached the path leading up to The Mall I turned round. Jack was watching me go. I walked on up the path, feeling uneasy. Was he making sure I left? And how odd had his behaviour been? It was almost as if I was bringing him something he didn’t want, rather than something that he desperately needed.

  In fact . . . I stopped. Wasn’t it kind of weird that Jack should have forgotten the disk in the first place? I mean, that ledge under his desk looked more like a hiding place than somewhere a disk might fall, unnoticed. And, now I came to think about it, the whole meeting was about handing it over and yet he’d clearly got all the way to the handover site without noticing he didn’t have it.

  I turned on my heel and headed back towards the bridge where I’d left him. Jack was still there, but he was no longer alone. He was talking to a tall, thin man with cropped black hair. So where was Geri? I couldn’t hear what the two men were saying out there by the water, but it didn’t look like a discussion on the best way to feed ducks.

  I crept along the row of trees lining the path. The thin man’s voice was raised now, but I couldn’t make out individual words. I edged closer, into the undergrowth that fronted the water. I climbed over the low fence that separated the path from the stream and crawled from bush to bush until I was close enough to listen in.

  ‘You’re sure this is the Medusa gene formula?’ the thin man said.

  ‘Yes.’ Jack sounded tense. He held out his hand. There was something in his palm. ‘It’s all here. The whole thing.’

  I crouched, stock-still, behind my bush. Jack had said the computer disk contained information about Viper. Not the gene formula. In fact, it had never occurred to me that there was a formula for the Medusa gene.

  ‘And this also explains how the gene code for Medusa causes whatever virus it’s implanted in to mutate and cause cancer in the mothers?’

  ‘Yes, though there’s no explanation as to why that happens,’ Jack said. ‘But all the important details are in there. Everything you need to know. And remember, Carson, the gene might kill the mothers, but it leaves the babies unharmed and fully skilled. Still, you know that from the recordings of Dylan and Nico that I sent you.’ Jack held out his hand again.

  Recordings? When had Jack recorded me using my telekinesis? My stomach twisted over as I remembered that first day in the garage at the mews house – and how Jack had filmed me moving that tyre around.

  Carson
took what Jack was holding out. It wasn’t the disk we’d found in William Fox’s notes. It was much smaller. Like a memory card for a phone or a camera.

  He peered at the tiny card more closely. ‘This can’t be the original,’ he said.

  ‘It’s not. I downloaded it from a disk I found in William Fox’s files.’

  So that’s why Jack hadn’t needed the disk. He’d copied the formula onto the memory card. And now he was giving the card to this man, Carson. But why? Did Carson work for Geri too? What about Viper? I thought that finding her was what Geri and Jack were interested in?

  ‘I’ll need the original, too.’

  ‘Sure.’ Jack nodded, but he didn’t take the disk I’d brought him out of his pocket.

  The man took out some kind of hand-held device and inserted the tiny memory card Jack had given him into the machine. As he pressed buttons and stared at the screen he spoke again, but more quietly. I could only catch the occasional word.

  I waited, frozen to the spot, as Carson took the card out of his device. He nodded and said something else I couldn’t hear.

  ‘That’s not what we agreed.’ Jack’s voice rose, bitter. He snatched the memory card back and shoved it into his wallet.

  ‘Give that back,’ Carson said.

  ‘Not until you agree to wire me all the money. Now.’

  ‘No,’ Carson snapped. ‘You’ll get the rest when I’ve verified the formula.’

  ‘I’m taking a huge risk bringing this to you.’ Jack was almost shouting now. He tucked his wallet, containing the memory card, into his inside jacket pocket. ‘I want my payment in full. Now.’

  Payment? Money? My head spun as it sank in. Jack was selling the formula. But . . . but . . . how did this tie in with everything he’d said about wanting to find Viper?

  And then I realised. It didn’t. Jack had never really been interested in finding Viper – or in helping any of us develop our abilities. He’d obviously only worked with me on my telekinesis for one reason – to win my trust so that I’d help him find and steal Fergus’s Medusa files.