Stealing a priest's robes, he gets as close as the steps before one of the guards recognizes the medallion he carries as being stolen.
Thorgrim and Rexor seize Conan, beat him, and drag him before Thulsa Doom, who chides him for stealing the Eye of the Serpent and killing the great snake. Conan replies that Doom killed his parents, but Doom did so much killing as a young man that he does not really remember the incident. He also explains that "steel is strong but flesh is stronger" a point he proves by coaxing one of his female followers to step off a nearby cliff, falling to her death.
Doom orders that Conan be crucified on the "Tree of Woe." Conan is left in the desert, nailed to the ancient tree. He is nearly dead when he is finally rescued by Subotai. Subotai and Valeria take him to Akiro for healing. The wizard tells them that this night the spirits of the underworld will come and try to take Conan's spirit back with them. Valeria says that she will fight them.
Akiro warns that the gods will extract a heavy price for defying them in such a manner, but Valeria tells him she is willing to pay it. They successfully fight the spirits and Conan recovers.
Conan finds that the Doom's mountain has cave entrances on the far side and these connect up with the interior of the temple. The three paint themselves with warrior camouflage and enter the temple through the rear, quietly killing the guards.
They work their way to the throne room were an orgy is in progress; the participants are also eating a stew made of human flesh. They set the drapes on fire and attack creating chaos in the throne room. Rexor recognizes Conan and attacks him with a double-bladed axe, he is soon joined by Thorgrim, wielding a large hammer. Conan is nearly overpowered, but the battle dislodges a pillar, which falls on Rexor and gives Conan a chance to flee.
Valeria grabs the princess and they escape. The girl is unwilling to leave, however, and Conan is forced to carry her on his shoulders. He is unable to kill Doom, who has changed himself into a giant snake and left the throne room through a small tunnel. The thieves get to their horses and ride away with the princess. Doom, back in human form, arrives at the rear entrance with Rexor and Thorgrim, swearing revenge.
Using an enchanted snake as a poison arrow, Doom manages to wound Valeria in the leg even at a great distance. She tells Conan about Akiro's earlier warning of paying the gods, then dies in his arms. Back at the place of the standing stones, Conan burns Valeria's body in a warrior's funeral. At the place of the scared standing stones, Conan, Akiro, and Subotai prepare a defense. Conan chains the princess to a stone on top of a hill tempting Doom to come and get her.
They set booby traps around the stones and place defensive spikes. Conan finally prays to his god, Crom, asking him to remember that today two will stand against many, and that if Crom doesn't wish to help Conan, so be it.
Doom comes with his lieutenants and a hoard of men. He stands on a distant hillside and watches the battle. Despite being outnumbered Conan and Subotai dispatch most of his troops. Thorgrim is killed by one of Conan's elaborate traps. As he watches Thorgrim die, Rexor, wielding Conan's father's sword, attacks and nearly kills Conan. He is about to deliver a killing blow when a Valkyrie-like figure intervenes, then asks Conan if he wants to live forever.
It is the ghost of Valeria, dressed in shining armor. She has fulfilled a promise she made to Conan that she would come back from the dead, if necessary, to fight by his side. Reinvigorated, Conan manages to slay Rexor and reclaim his father's sword, but the fight leaves him injured, and the sword broken. Seeing that his men have lost, Doom decides that if he cannot have the princess, nobody will, and prepares another enchanted snake arrow to kill her despite the girl's desperate pleas.
Subotai, however, races up the hill and is able to block the arrow with his shield at the last moment. Doom rides off, and the princess now appears to be free of his indoctrination. The scene switches to the mountain temple were Doom is conducting a night ceremony. Throngs of his followers stand on the temple steps holding lit torches. Conan appears behind Doom. When Doom sees him he tells Conan that Conan cannot kill him because Doom is the only purpose Conan has in his life.
For a moment Conan is taken in by Doom's enchanted voice and hypnotizing stare like his mother was years before, but then breaks free from the spell and beheads Doom with his father's broken sword. He holds Doom's head up to the crowd, and then tosses it down the steps. Seeing that their leader was not immortal as they thought, the crowd douses their torches in the temple's pool and all quietly depart.
Conan sits on the steps of the temple, alone, thinking about what to do next. He then proceeds to destroy the temple and returns the princess to her father. Akiro speaks, telling us that Conan will have many adventures. The scene switches and we see an older Conan sitting on a throne. A text crawl informs us Conan will one day become a king by his own hand, but that this is a story for another day.