The young man looked at him aslant. “Shouldn’t we be? I tell you, Enzkr, if you are thinking of Ivar’s treasure you had better cut your thoughts right out of your head. It will be less painful that way. Did you even hear what Ivar did to the Irish king at Knowth?”

As they walked round, he told him in detail what Ivar had done to kings and lesser men who had displeased him. Shef took little notice, looking with great interest at the camp. The tales were clearly meant to frighten him.

The ships, he thought, were the weak point of the camp. Space had to be left clear for them to be drawn up on the muddy banks, so there could be no fortifications there. The ships themselves represented a sort of obstacle, but they were also the Vikings’ most precious possession. If anyone got past the riverbank-guards, they could be in among the ships with torch and axe, and they would be difficult to dislodge.

The gate-guards were a different matter. Surprising them would be hard. Any fight would be on level ground and on even terms, where the Vikings’ great axes and iron-shafted javelins would have easy play. Anyone who did manage to get through them would in any case only find himself fighting his way through rank after rank of warriors, in a tangle of tents and ropes.

The pens, now … They occupied an area of their own near the east wall: a sorry strip of posts hammered into the ground, leather ropes binding them together. Inside, men huddled under makeshift coverings of canvas against the rain. Iron fetters on their feet, iron manacles on their hands. Held together, though, Shef noted, only by leather. Chain was too dear. But by the time a man had chewed through the leather bonds, even the least alert guard should have noticed—and penalty for any disobedience in the slave-pens was fierce. As Shef’s guide pointed out, if you marked up a slave too much you couldn’t sell him anyway, so you might as well go ahead and finish the job to frighten the others.

As he peered over the logs into the pen, Shef noticed a familiar-looking head lying on the ground, its owner sunk in a depth of despair: a blond head, curls matted with grime. His half brother, son of the same mother. Alfgar. Part of the prey of Emneth. The head stirred as if sensing the eyes upon it, and Shef dropped his gaze instantly, as he would have done had he been stalking a doe or a wild pig of the marshes.

“You haven’t sold any slaves since you arrived?”

“Nay. Too much trouble getting them out to sea, with the English ambushing all the time. Sigvarth owns that lot.” The young man spat again, eloquently. “He’s waiting for someone else to clear the road for him. Will, too.”

“Clear the road?”