The hawkmen capture Flash, Thun, Barin and Aura and fly them to King Vultan's mile-high, suspended sky city where the winged monarch announces he will marry Aura and sends Flash and his friends to slave in his atomic furnaces. Back at the palace Emperor Ming commands Dale to marry him and advises Dr. Zarkov that earth's days are numbered. In a spectacular sky battle Vultan's hawkmen are no match for Ming's rocket forces, who blast the hawkmen's sky city into rubble. Ming rescues his daughter Aura as his metalmen capture the city. This chapter ends with sky city in ruins and Vultan, Barin, Thun and Flash departing for Arboria where they will map their revenge on Ming the merciless.