The narrative hinges on Jason's vow to wreak vengeance on his father for abandoning his mother. But his father dies, and Jason turns his desire for revenge against Sunlocks, his father's son of another wife. Both Sunlocks and Jason are in love with Greeba, daughter of the governor of the Isle of Man. Sunlocks and Jason go to Iceland, and are confined in prison. Jason not knowing Sunlocks, saves his half-brother from death in the mines. Jason is freed, but Sunlocks is condemned to death. Greeba pleads for Sunlocks' life, and Jason sacrifices himself by taking Sunlocks' place and dying for him. -- Wikipedia