It is early spring, a turbulent, perilous time of sudden storms, frozen river fractures and drifting ice. Fleeing from a demon intent on devouring his souls, Wolf is swept out to sea far from the forest and his pack. The ocean, too, teems with danger: sea wolves, sharks and hunters of the deep, and the demon is gaining ground. Torak and Renn must race to save their pack-brother, battling the harsh icy waves and merciless torrents. If they can't find Wolf in time, the bond between them will be severed forever....

For two summers Torak and Renn have been living in the Forest with their faithful pack-brother, Wolf. But their happiness is shattered when Renn realises Torak is in danger – and she's the threat. When she mysteriously disappears, Torak and Wolf brave the Far North to find her. At the mercy of the Sea Mother and haunted by ravenous ice bears, their quest leads them to the Edge of the World. There they must face an enemy more evil than any they've encountered.

As winter approaches and Souls' Night draws near, the Eagle Owl Mage holds the clans in the grip of terror. To fulfill his destiny, Torak must seek his lair in the Mountain of Ghosts. He must defy demons and tokoroths, and find his way through the Gorge of the Hidden People. Wolf must overcome terrible grief. Renn must make an agonizing decision. And in the final battle against the Soul-Eater, Torak must face the most heartrending choice of all.

Torak has survived the summer and his heart-stopping adventure in the Seal Islands. He and Wolf are together again. But their reunion is all too short-lived. As mid winter approaches, Torak learns the worst from the White Fox clan. The Soul-Eaters have snatched Wolf and will sacrifice him. Desperate to rescue him, Torak hatches a perilous plan, one that he must carry out alone. He will find the Soul-Eaters and infiltrate their cult.

When he was outcast, Torak was the hunted one. The following spring, he becomes the hunter when he swears to avenge the killing of one of his closest friends. To fulfil his oath he must brave the hidden valleys of the Deep Forest, where the clans have reverted to the savagery of an earlier time. Here, Torak finally learns why he is the Sprit Walker and discovers the true cost of revenge.