Conan, leader of a band of Kozaki mercenaries in the service of King Kobad of Iranistan, quarrels with his employer over the king's command to capture Balash, chief of the Kushafi nomads and Conan's friend. Instead, Conan has his men warn the Kushafi. In the Gorge of Ghosts, the two armies are attacked by members of the Sons of Yezm, a cult of assassins whose symbol is the Flame Knife. The cultists kidnap Nanaia, Conan's current girlfriend. The Cimmerian tracks them to their stronghold, where he becomes embroiled in a conflict with his old rival Olgerd Vladislav, an opponent first encountered in Howard's story "A Witch Shall be Born".
Sources
Laughlin, Charlotte; Daniel J. H. Levack (1983). De Camp: An L. Sprague de Camp Bibliography. San Francisco: Underwood/Miller. p. 54.