From the roof I could see what Snorri had described, and nothing more. Perhaps what he saw had been the sum of them. Heart pounding, and shaking with both the cold and with the thought of what the dark might hide, I made a circuit of the guard wall. Nothing. No other light. Nothing to see at all. That worried me, both in general and for some other reason I couldn’t quite put my finger on.

For long minutes only the wind howled, the Vikings held their ranks in the lee of the walls, the dead behind them, and nothing moved. A dread grew in me, but it hardly required any extra malign influence for that. There were dead things out there, wanting us to share their state; only a madman wouldn’t be quaking.

With only the lights to watch, I watched the lights. I wondered how I could ever have fooled myself they were just embers from the bone-fire blown out across the ice field. The mind spends half its time in self-deception, it seems. Or maybe I’m deceiving myself . . . I watched the lights a moment longer, then slapped my brow. It’s not often that people actually do slap their brow when a sudden realization illuminates their skull from the inside, especially without an audience. But I did it. And then I ran down the icy stairs, two and three at a time, swearing at the pain with each impact.

“What? What is it? What did you see?” All three of them together as I hunched over my hurt, clutching my ribs, fighting to draw breath.

“Give him some room.” Snorri, stepping back.

“I—” The cut on my leg had broken past the stitches Ein had set there while I slept, blood running down my thigh.

“What did you see?” Tuttugu, white-faced.

“Nothing.” I gasped it out and drew a breath.

“What?” Three blank looks.

“Nothing,” I said. “Just the Hardanger men’s lanterns.”

Another moment of incomprehension.

“There’s no fire on the wall.” I pointed in the rough direction of Snorri’s great pyre.

“It can’t have gone out,” Ein said. “It’ll still be hot this time tomorrow.”

“Yes.” I nodded. When I came down to report the visitors from the Bitter Ice, the bone-fire had been ten yards of orange embers with flames licking over them when the wind gusted.

“I’ll go check.” Ein took up a lantern from the mantelpiece and went to the heavy door that connected back to the corridor and halls beyond. A pounding from down below stopped him in his tracks. It sounded more like a battering ram than the crash of shield on wood that we’d heard before.

“Tuttugu! Oil!” And Snorri hauled the cover from the murder-hole. He stared down, brow furrowing. “There’s nothing th—”

BOOM!

The sound of the impact drowned him out.

“Hel! It’s coming from the inside!” Snorri whipped round towards Ein, who stood at the doorway with his back towards it.

“I’ll find out—” Ein bit his sentence short and staggered forwards, accompanied by a splintering thud. Something sharp and thick and gore-coated now jutted from beneath his sternum. A moment later the door came off its hinges and the horror beyond shook the door and Ein’s corpse from the appendage it had impaled them both with.