He jerked his thumb at the little cluster a few yards away from them on the wall: Wulfhere the archbishop with a knot of black monks, among them the scrawny pallor of Erkenbert the deacon, now master of the mint.

Ivar laughed, suddenly. His three brothers looked at him with unease.

“We don’t need to fight them,” he said. “Their own bane marches with them. For some it does.”

Wulfhere too scowled at the retreating column. “Some of the blood-wolves gone,” he said. “If they had gone earlier we might never have needed to treat with the rest. But now they are within our gates.” He spoke in Latin, to make sure hostile ears did not overhear.

“We must, in these days of strife, live by the wisdom of the serpent,” replied Erkenbert in the same language, “and by the cunning of the dove. But both our foes without the gates and those within may yet be overcome.”

“Those within I understand. There are fewer of them now, and they may be fought again. Not by us in Northumbria. But by the kinds of the South—Burgred of Mercia, Ethelred of Wessex. That is why we sent south the crippled thane of East Anglia, slung between his ponies. He will show the southern kings the nature of the Vikings and wake their drowsy spirits to war.

“But what, Erkenbert, is your plan for those now marching away? What can we do in dead of winter?”

The little deacon smiled. “Those marching in winter need food, and the ravagers of the North are accustomed to take it. But every mouthful they steal now is one less for a man’s children before spring comes. Even churls will fight with that incentive.

“I have seen to it that the word of their coming will run before them.”

The attacks began as the short winter daylight seeped from the sky. At first they were little more than scuffles: a churl appearing from behind a tree, launching a stone or an arrow downwind, and then fleeing hastily, not even waiting to see if he hit the mark. Then a little knot of them coming in closer. The marching Vikings unslung bows if they had them, tried to keep the bowstrings dry, shot back. Otherwise they ducked heads behind shields, let the missiles bounce off, shouted derisively to their foes to stand and fight. Then one, irritated, launched a spear at a darting figure who seemed to come too close, missed and plunged off the track with a curse to recover it. For an instant a snow-flurry hid him. When it cleared he was nowhere to be seen. With difficulty his crewmates halted the column, plodding, head-down, and set off grimly to rescue him, a group thirty strong. As they lurched back with the body, already stripped and mutilated, the arrows came whipping from behind them again, out of the murk of the dying day.