The great host that Mance Rayder had gathered from a hundred quarrelsome peoples fell upon Castle Black at last, and by design it came from two sides at once. While the King Beyond the Wall marshaled the bulk of his strength in the haunted forest to the north, meaning to break the ice-locked gate and pour through the Wall itself, a chosen band of raiders and Thenns had already crossed the Wall far to the east and marched south to strike the undefended castle from behind. Castle Black had no southern wall to speak of, for in eight thousand years no enemy had thought to assail it from the lands of men, and the garrison that held it was pitifully thin: a few score brothers, most of them green boys or old men, stiffened by the cunning of the one-armed armorer Donal Noye.
The defense fell in large part to Jon Snow, newly returned from his time among the free folk and still under a cloud of suspicion, for he alone had marched with Mance's host and knew its ways. He counseled the garrison, took command in the confusion of the fighting, and held the top of the Wall and the gate below through days and nights of assault. Donal Noye died in the dark of the winding tunnel, slaying the giant-blooded Thenn captain even as he was crushed, and many brothers fell upon the ice and the crooked stairs. It was in this fighting that the wildling girl Ygritte, whom Jon had loved beyond the Wall, was slain by an arrow, dying in his arms with a jest and a reproach upon her lips.
Against every reckoning the castle held. The wildlings hurled themselves at the gate and the switchback stair and could not force a passage; the Watch answered with arrows, boiling oil, and a scythe of iron swung along the base of the Wall, and Mance's mammoths and giants broke upon the ice without carrying the day. When it seemed the sheer weight of the free folk must at last tell, the assault was broken not by the garrison's strength but by a stroke none had foreseen, the arrival of a host out of the south. The maesters remember the stand as one of the great feats of the latter-day Watch, a few hundred sworn brothers holding the northern gate of the realm against a nation in arms.