But the thing that puzzled me most was why? Why dress up in a wig and a Pink Floyd T-shirt and spend the afternoon hanging out in an empty cabin? What was she doing there? And if it was so secret, why answer the door at all?

As the last question ran through my head, I had a sudden flash of myself knocking on the door—one, two, three . . . pause, and another bang, and the way the door had been snatched open as if someone had been waiting for that final knock. It was an odd knock, idiosyncratic. The kind of knock you might use if you were arranging a code. Was it possible I had, completely accidentally, stumbled on a prearranged signal for the woman in the cabin—Anne Bullmer—to open the door?

If only. If only I’d just knocked twice like any normal person—or even once. I would never have known she was there, never have put myself in this position where I had to be locked up—silenced . . .

Silenced. It was an uncomfortable thought, and the word stuck in my head, reverberating there like an echo.

I had to be silenced. But silenced for how long? Locked up here until . . . what? Some prearranged deadline had passed?

Or silenced . . . permanently?

Supper was white fish in a sort of cream sauce, with boiled potatoes. It was cold, congealing around the edges, but I was hungry. Before I ate I looked at the pill in my hand, wondering what to do. It was half my normal dose. I could take the whole pill now, or I could split it, and start building up a reserve in case . . . but in case what? I could hardly escape, and if Anne decided to stop dispensing the pills, I would run out long before she took pity on me.

In the end, I gulped down the whole thing, reasoning that I had a deficit to make up. I could start biting them in half tomorrow, if it seemed important. I felt better almost immediately, though I knew, logically, that it couldn’t be the pills. They didn’t absorb that fast, and the effect took a while to build up in my system. Whatever I was experiencing was completely placebo-based. At this point, though, I didn’t care. I would take what I could get.

Then I started picking at the lukewarm supper. As I sat on the bunk, chewing the tepid, gluey potato slowly, in an effort to make it less unappealing, I tried to rearrange the pieces of the puzzle I had assembled so painstakingly inside my head.

I knew now what that derisive snort meant when I had said Who is it up to? Ben?

Poor Ben. I felt a rush of guilt that I had been so quick to judge him, and then another rush, this time of anger. I’d been so focused on Anne’s chance mention of a male accomplice that it had never occurred to me that Anne herself might have been the one to run quickly down the spa stairs while her varnish was supposed to be drying and scrawl those words. Stupid, stupid Lo.

But stupid Ben, too. If he hadn’t spent so many years belittling my feelings and if he hadn’t been so eager to spill the beans to Nilsson, instead of supporting my story, then I might not have been so quick to jump to conclusions.

I knew now who he was. It must be Richard Bullmer. He owned the boat. And of all the men on the ship, I could imagine him planning and carrying out a murder better than anyone else. Certainly better than fat, fussy Alexander or the lumbering, bearlike Nilsson.

Except that no murder had taken place. Why did I have to keep reminding myself of that fact? Why was it so hard to grasp?

Because you’re here, I thought. Because whatever you saw—whatever happened in that cabin—it was important enough that they would lock you up here and prevent you from going to see the police at Trondheim. What had happened? It must be something so high-stakes that they simply couldn’t afford to let me talk about it. Was it smuggling? Were they throwing something overboard to an accomplice?

It’ll be you next, you stupid bitch, said the voice inside my head, and an image of myself falling through deep water shot through me, like an electric shock deep in my skull.

I winced and gritted my teeth, forcing myself to swallow another glutinous mouthful of potato. The ship heaved, and nausea swilled around in the pit of my stomach.

What was going to happen to me? There were only two possibilities—they were going to let me go at some point. Or they were going to kill me. And somehow, the first one didn’t seem very likely anymore. I knew so much. I knew about Anne. I knew she wasn’t nearly as ill as she pretended. And they could not afford for me to get out and tell my story—a story of kidnap, imprisonment, and bodily harm—though would anyone believe me?

I touched my fingers to my cheek, where the blood was still caked from where she’d whacked me into the doorframe. I felt suddenly gross—dirty and sweaty and blood-smeared. Anne—judging by her previous timings—wouldn’t be back for hours.

There wasn’t much I could do to improve my lot, stuck in this two-meter coffin. But at least I could keep myself clean.

The jet was nothing like the one in my suite upstairs. Even turned up full it was a tepid trickle, but I stood underneath it for so long I felt my fingers wrinkle into mush. The clotted blood on my hand dissolved into the water and I shut my eyes and felt the warmth pour through me, seeping into my muscles.

When I climbed out I felt better, more like myself, washed clean of some of the fear and violence that had marked the last few days. It was putting my clothes back on that made me really realize how far I’d sunk. They stank—not to put too fine a point on it—and were stained with blood and sweat.

I lay down on the bunk and shut my eyes, listening to the steady thrum of the engine and wondering where we were. It was Wednesday night—or maybe even Thursday morning now. From what I could remember we had only a little over twenty-four hours of this trip left. And then what? When the boat got into Bergen on Friday morning, the other passengers would leave and with them would go my last hope of someone realizing what had happened.

For twenty-four hours I was probably safe. But after that . . . Oh God, but I couldn’t think about that.

I pressed my hands into my eyes, listened to the blood roaring in my head. What should I do? What could I do?

If Anne was telling the truth, hurting her wouldn’t achieve anything. There was another locked door the other side of this one, and very likely other codes on the exits. For a minute I wondered if I got out into the corridor, could I find and smash a fire alarm before Anne caught up with me? But it seemed like too long a shot. From what I’d seen of Anne’s strength and quickness, I was unlikely to get that far.

No. My best chance was simple—I had to get Anne on my side.

But how? What did I actually know about her?

I tried to think about what I knew about Anne Bullmer—her fantastic wealth, her lonely upbringing, trailing around the boarding schools of Europe. It was no wonder it had taken me so long to make the connection. The rake-thin, sad-eyed woman in her gray silk wraps and designer headscarves—yes, somehow that fit with what I’d been told. But I could not make one word of what Ben had said connect with the girl in the Pink Floyd T-shirt, with her mocking dark eyes and cheap mascara. It was like there were two Annes. Same height, same weight, but that was where the similarity ended.

And then . . . something clicked.

Two Annes.

Two women.

The gray silk robe that matched her eyes . . .

I opened my eyes and swung my legs over the side of the bunk, groaning with my own stupidity. Of course—of course. If I hadn’t been half-dead with fear and panic and the pain in my head, I would have seen it. How could I not have thought of it?

Of course there were two Annes.

Anne Bullmer was dead—had been since the night we left England.

The girl in the Pink Floyd T-shirt was very much alive, and had been impersonating her ever since.

Same height, same weight, same broad cheekbones—it was only the eyes that didn’t match, and they had taken a calculated risk that no one would remember the features of a woman they’d barely met. No one on board knew Anne before the trip. Richard had even told Cole not to take any photographs of her, for Christ’s sake! Now I understood why. It wasn’t to protect a woman self-conscious about her appearance. It was so there would be no compromising photographs for his wife’s friends and family to puzzle over afterwards.

I shut my eyes, my fingers gripping my hair so hard that it hurt, tugging painfully on my scalp, trying to work out what must have happened.