In San Francisco, they learn that Bessie the Ophiotaurus is the monster Artemis was searching. This is because sacrificing it and burning its entrails will give a person the power to destroy Olympus. They ask for the help of Annabeth's father who gives them a car. They travel to the Garden of Hesperides, where Zoë meets her sisters. She is poisoned by a dragon called Ladon. They continue to the Mountain of Despair on California's Mount Tamalpais, where Mt. Othrys, the Titan capital, is now present. From the top of the mountain where Atlas held up the sky, they see Artemis holding the sky. Annabeth is held captive by Luke. Percy takes the burden—the Titan's curse—from Artemis. After this, a fight breaks out. Atlas (the General of the Titans) kills his daughter Zoë by throwing her against rocks. Artemis tricks Atlas into taking his burden from Percy. Luke falls from a cliff during a battle with Thalia, and Percy thinks that he is dead. They go to Olympus and they keep Ophiotaurus there and at that party Percy is told by Annabeth that Luke has survived.