[1] After successfully fulfilling his commission to overthrow a tyrannical baron in Koth, Conan travels into Baalur, a city-state in Shem.

Zeriti seeks to settle a score dating from Conan's previous encounter with the two women, told in the story "Hawks Over Shem", and her curse is transforming Rufia's subjects into hideous zombies.

With an army of Baalurian soldiers, Conan begins his journey to retrieve a white lotus, the primary antidote for removing Zeriti's cruse, said to only bloom near the source of the Styx, the infamous black river.

His army marches across the city-state of Nedrezzar before reaching the port city of Asgalun, where they set sail for the Styx, which serves as a boundary between Shem and the ancient kingdom of Stygia.

The expedition encounter many dangers along the way, including pirates, hostile local rulers, religious cults, and cannibals before reaching the Styx's headwaters.