An unnaturally long and bitter winter has fallen over all of Mithgar, and there are rumors of Vulg attacks on Warrow farms. So in the Boskydells, all young male Warrows are training to become Thornwalkers and watch over their homeland. Tuck Underbank, Danner Bramblethorn and several others pack up and depart, leaving behind Tuck's dammia (girlfriend/lover) and all their families.
After a lethal encounter with some Vulgs, which kills one of their number, the Warrows and their new leader Patrel Rushlock arrive at the Spindle Ford and take up their guard duties. A messenger arrives from the king's fortress Challerain Keep, revealing that Modru of Gron is attacking the peoples of Mithgar, and asking the Boskydell for some help. Unfortunately he and a friend of Tuck's are killed when a Vulg attacks, knocking them into a frozen river. Tuck is the only one who survives.
Danner, Tuck and Patrel are among the Warrows who go to Challerain Keep, where they become acquainted with High King Aurion Redeye, his son Prince Igon, his future daughter-in-law Princess Laurelin, as well as the elf lord Gildor Goldbranch and Hrosmarshal Vidron. They also are invited to Laurelin's nineteenth birthday party, but during the party a messenger arrives, saying that the fortress is about to be attacked.
Tuck and the Warrows take part in the battle against Modru's Horde, but he becomes lost and ends up inside a crypt with the crown prince, Galen, where Tuck retrieves a small red arrow. He and Galen manage to escape the slaughter as Challerain Keep is destroyed, and end up in an elven village where they are cared for and fed. But then it is revealed that Igon was found unconscious in the snow nearby, and Gildor arrives to say that Aurion is dead.