The Shadow Tower guards the western marches of the Wall, where the mountains close in and the Gorge cuts deep, and the only crossing thereabouts is the narrow span the brothers name the Bridge of Skulls. As Mance Rayder gathered the free folk into a single host and turned them toward the Wall, he sent one of his fiercest captains, the raider called the Weeper for the tears of blood that ran ever from his eyes, to force a passage in the west while the King Beyond the Wall pressed the greater assault to the east.
The wildlings came against the bridge in strength, seeking to storm the crossing and take the Shadow Tower from behind. There Ser Denys Mallister, the aged and honorable commander of the tower, met them with the sworn brothers under his command. The fighting upon the bridge was close and bloody, sword against club and stone, and the brothers held the narrow span against numbers that should by rights have overwhelmed them. When the day was done the Weeper's men were thrown back and the crossing kept, though many good men of the Watch were slain, and the tally of the western war was carried east to Castle Black to add to the sum of the brotherhood's peril.