When the Mongaul attack the medieval fortress of Parros, a prince and princess flee. Now orphaned, they must survive a dangerous land filled with monsters and magic. But in the middle of a dark forest, they are discovered by a warrior who has no memory of his life before and is imprisoned within a leopard mask. The three form a bond and together, they fight for survival against dark forces and the ruthless kingdom of Mongaul.

When Ruto discovered Guin and the royal orphans in the forest, Guin is forced to surrender to save the children’s lives. Ruto then takes his prisoner to the dark fortress of the lord Vannon, a powerful spell-wielding dictator. There, Vannon pits Guin against the monstrous grey ape in a gladiatorial duel to the death.

After Guin defeats the grey ape, Vannon sends in another opponent, the dashing swordsman Istavan. But when Vannon experiences strange pain, the match is called off and Guin and the royal orphans are imprisoned.

Guin and the royal orphans survive their deadly fall from Vannon’s flaming castle. And though the swordsman, Istavan, has joined them, they are far from safe. For now they must cross the deadly, monster-filled River of Darkness to continue on their journey. While navigating the dangerous waters, the warrior princess from Mongol stumbles upon them—and takes special note of the trespassers.

Guin begins to have glimpses of his past life and when he mentions "Landlock," Istavan tells him it is not a place but a pirate ship, a vessel unlike any he has ever seen. Before they can investigate this memory further, they are discovered by Mongaul troops and taken captive by the warrior princess of Mongaul, the beautiful but powerful Amnelis.

Amnelis prepares to bring war against the Sems to gain control of the magical tower and use its strange power to control all of the Middle Country. But Guin has plans to help the Sems defeat the Mongaul armies. The frightening mystic, Cal Moru, reveals how he transformed into such a terrifying creature.