The same wind, that dawn, blew across the bows of the forty dragon-boats cruising down the English coast from the Humber, almost in their teeth, making it impossible to rig sail. Ivar Ragnarsson, in the prow of the first boat, did not care. His oarsmen were rowing at their paddling-stroke, which they could keep up for eight hours a day if need be, grunting in unison as they heaved their oars through the water, feathering with the ease of long practice, continuing their conversations with a word or two as they swept them back, dipping and heaving again.

Only in the first six boats was there extra work for the men. In each, a ton and a half of dead weight squatted, carefully stowed before the mast: the onagers of Erkenbert, all the forges of York Minster had been able to turn out in the weeks Ivar had given them. Ivar had raged furiously about the weight, demanded that they be lightened. Impossible, the black archdeacon had replied. This is the way they are drawn in Vegetius. More convincingly, lighter models had knocked themselves to pieces in a dozen shots. The kick of the wild ass that gave these machines their name came when the throwing-arm struck the crossbeam. If there were no crossbeam the stone would not be hurled out with its astonishing force and velocity. A light crossbeam, however padded, would crack.

Ivar’s meditations were interrupted by loud retching from behind him. Each onager was served by a dozen slaves from the minster; in command of them all, torn deeply against his will from the studies and library of the minster, Erkenbert himself. Now one of the lubbers had succumbed to the long, North Sea swell and was vomiting his heart out over the side. The wrong side, naturally, so that the meager contents of his stomach blew back over the nearest rowers, provoking shouts and curses, disruption of the long, automatic rowing-stroke.

As Ivar stepped toward the disturbance, hand dropping to the gutting-knife at his belt, Hamal the horse-swain, the man who had saved Ivar from the lost battle at March, moved quickly. The slave grasped the man by the scruff of his neck. A violent blow across the side of the head, repeated as Hamal heaved the wretched man off his feet and flung him across the thwarts to the lee side, there to retch in peace.

“We’ll have the hide off him tonight,” said Hamal. Ivar stared unblinkingly for a moment, knowing well what Hamal was doing. Decided to leave it for the moment. Turned back to his thoughts in the prow.