‘When are you coming home?’

‘I don’t know,’ I admitted. ‘We have to wait for a new plane.’

‘I miss you.’

‘I miss you too.’ But I was speaking to no one: the screen had gone blank. I thought the storm must have knocked out the Internet, but a few moments later a sentence appeared in the box next to the video window.

With the limited bandwidth, and Luke’s typing, the letters stuttered across the screen. I found myself getting impatient with him, and then ashamed for being impatient. It wasn’t his fault. Since it ended with Louise, I’ve been reliant on Luke for so much. It’s too much weight to put on an eight-year-old.

Our conversation quickly collapsed into monosyllables. He must be getting impatient, too. I tried not to take it personally, though you always do, with your children.

The connection was so slow, I began leafing through Hagger’s notebook while I waited. Only marginally less frustrating, but at least it was something to do.

What is X?

Maybe Anderson?

Absorbed, I didn’t realise Luke was waiting for me to reply. I looked up to see a line of gibberish on the screen.

At first I thought the storm had mangled the transmission. Then I realised it was a riddle, a fad they had been going through at school when I left. Abbreviating sentences and making you guess what it stood for. The sort of unwinnable game schoolboys love.

I thought about it for a little bit, but I didn’t have the patience. Who knows what an eight-year-old’s mind will come up with?

The reply took a good five minutes to come through. Maybe he’d wandered off, or started playing his Nintendo.

I thought of the bear I’d seen with Ash. I wished I’d taken a picture for Luke.

The moment we disconnected, I wished I’d persevered, slow connection and all. I missed him terribly. I read over the last few sentences still up on the screen.

It made me think of a line from Quam’s ludicrous form.

An acronym for a memorable sentence, suitably modified, would be advisable.

I looked down and saw Hagger’s (mis)quote on the inside cover of the open notebook. Some Say the World Began In Fire …

Under no circumstances should you ever write your password down.

Hagger’s computer took ages to boot, the way computers do when they haven’t been used in a while. As if they’ve got lazy. I paced around the tiny room, staring out the window. The snow was so thick in the air you couldn’t see anything; the closest to night there’d been since I woke up out of the coma.

Some Say the World Began In Fire, Some Say In Ice.

There was still some work to do to fit it to Quam’s rules, and I couldn’t afford too many wrong guesses. If the machine locked me out, I’d have a hell of a job explaining it to Quam. I played around with various combinations of capitals and lower case, possible substitutions of numbers for similar letters. A lot of options, lots of S’s and I’s that might turn into 5’s and 1’s.

I thought I remembered Hagger was born in 1955, so I replaced the two leading S’s with 55. Tried it, heart in mouth, and nearly died when the computer rejected it. Tried it again, this time also replacing the S’s of the second ‘Some Say’.

Logging on …

I knew something wasn’t right the moment the main screen appeared. Anyone’s machine, you’d expect to see a clutter of icons, files and folders. Certainly, Hagger wasn’t the sort of person to keep a tidy desktop.

This was empty.

I searched the hard drive. The file structure was still there — directories for experiments, for data, for papers — but each one was empty. Systematically stripped bare.

I could feel my heart accelerating. The wind moaned strange harmonies outside; loose ice rattled the roof so loud I thought it was in the room with me. I looked over my shoulder, but there was nothing there. Nothing there. That was the problem. As fast as I could recreate Hagger’s experiments, someone was tearing them up. How long before they caught up with me?

One of the few programs left on the machine was the email client. I tried it, more in despair than hope, expecting another empty window. Instead — bingo. Whoever had wiped the hard drive — maybe he didn’t have time, maybe he didn’t care — hadn’t deleted the old emails.

I scanned the subject headings, feeling more like a thief with every passing second. At least at Zodiac you don’t get the routine admin stuff that kills so many office hours, and Hagger had kept his account pretty pure, work-wise. Even so, the messages mount up when you’ve been dead for a week.

I could say, for dramatic effect, that I nearly missed it. That wouldn’t be true. It’s hard to miss a message headlined (all capitals) URGENT — NATURE — RETRACTION. I opened it at once.

It was from a colleague of Hagger’s, at Cambridge. A scientist of the old school, he didn’t mince his words. He’d reanalysed the samples Hagger had used for his famous experiment. He’d put them through a mass spectrometer.

I should have turned on the light. My head hurt from the strain of reading in the dark; my eyes were spotty with tiredness. I felt sick, confused and scared.

If Hagger doped his samples … In a way, I felt the same as the day that Louise told me she was leaving. The world upended, as if gravity itself turned out to be a gigantic hoax that everyone else was in on, and no one had had the guts to tell me. After all, it was Hagger who drilled into me, in the dog days after my first, anticlimactic experiments, that there are no short cuts in science; Hagger who taught Introductory Ethics with missionary fire; Hagger whom I couldn’t look in the eye after the Pharaoh scandal.

He was pushing sixty, and he hadn’t had a hit in years, said that cruel part of my brain, the cockroach part that could survive a nuclear war. He needed one more big grant to carry him over the line, earn his pension, or they’d have put him out to pasture.

I still wasn’t sure I believed it. In all the time I’d spent with his lab notebook, I hadn’t seen anything that suggested a man with something to hide. More the opposite: a man who knew something was wrong but couldn’t work out what it was.

But that wasn’t the most important thing.

I printed off the message, in case whoever’d wiped the computer came back for the emails. Judging from the time-stamp, it must have been one of the last messages Hagger read. I didn’t want it to be my last, too.

‘Got anything interesting there?’