The story begins in an Argos port where Conan forcefully demands passage aboard a sail barge, the Argus, which is casting off for southern waters to trade beads, silks, sugar and brass-hilted swords to the black kings of Kush. At first, the captain of the barge objects to his demand to travel without paying for the passage, and Conan threatens him and the crew with his drawn sword. Eventually the captain agrees to let Conan stay on board, since "It would be useful to have a fighting man on the voyage" and eventually Conan and the captain, named Tito, become quite friendly. The captain is soon informed that Conan is fleeing the civil authorities of Argos due to a court dispute in which Conan refused to betray the whereabouts of a casual friend to a fascistic magistrate (although no actual political reference is hinted in Howard's story) and instead drew his sword and killed the magistrate - whereupon he had to swiftly flee. It is emphasized that at this moment Conan was a complete land-lubber, with no previous experience or knowledge of the sea.
Upon reaching the pirate-infested waters of Kush, their trade ship is attacked by the infamous reavers led by B lit, the Queen of the Black Coast. B lit and her ebony-skinned warriors slaughter the crew of the Argus, who are no match for the ferocious pirates. Conan tries to rally the crew after the captain was killed, and when the fight becomes clearly hopeless he manages to jump aboard the pirate ship and sell his life dearly. Conan kills many of the pirates, fully expecting to be overwhelmed and killed - whereupon B lit suddenly orders her crew to step back and spare Conan, being impressed with the Cimmerian's courage and ferocity (and being sexually attracted to him, as she immediately and forthrightly declares). B lit offers Conan the chance to sail with her, be her chosen mate, and help lead her fierce warriors. Oddly smitten by this fiery woman, Conan agrees and, for a time, they raid the Black Coast together brutally pillaging coastal towns and instilling fear into the superstitious natives.
Soon, the Hyborian legends begin that the she-devil of the sea, B lit, has found a mate, Conan, an iron man whose wrath is that of a wounded lion. Survivors of butchered Stygian ships curse the name of B lit and her Cimmerian warrior with fierce blue eyes.
Sailing up a nameless river, B lit and Conan encounter ancient ruins in which is found a lost treasure, a winged monstrosity and skulking hyenas that were once men. Despite the bizarre murders of their crew and the various horrors lurking in the jungle, B lit and Conan still find time for a thorough theological discussion, comparing Conan's grim god Crom with B lit's more ambiguous Semite deities - all of which they discuss in between continuing their sexual romance which is alluded to by Howard as having sadomasochistic undertones. In a moment of passion, B lit promises that even death could not keep her from Conan's side, a promise which she must keep far sooner than she expects.
Despite her intense love for Conan, B lit is soon captivated by a cursed jeweled necklace found among the lost treasure which seemingly instills the wearer with a mix of madness and monomania. In such a twisted mental state, B lit issues faulty orders. Given the constant bizarre dangers and her own madness, her crew is soon decimated and B lit herself is hanged by the winged monster. Driven to rage and now alone, Conan confronts her supernatural murderer. He is on the verge of being slain when the spirit of B lit intervenes. Conan slays the winged horror and leaves the ruins in B lit's ship with her corpse.
The story closes with Conan giving B lit a Viking funeral - setting on fire the ship, with her surrounded by all her treasures - and reflecting upon his loss.
Output: What happen  when the trade  ship got to water of Kush?