Once there, Percy seeks out Nereus and learns that the monster Artemis was hunting is Bessie, the monster he saved back at camp with Blackjack, who is an ophiotaurus. After a final encounter with Dr Thorn in which Percy pleads with Mr D to help him defeat the manticore, Grover heads back to Camp Half-Blood with Bessie. Zoë, Percy, and Thalia go to find Frederick Chase, Annabeth's father, in the hope that he will help them reach their final destination: Mount Tamalpais, the modern location of the Titans' fortress on Mount Othrys. With Professor Chase's car, they travel to the Garden of Hesperides. Zoë is wounded by the dragon Ladon while they pass through. At the place where Atlas once held up the sky, the group finds Artemis now doing his job. After seeing Annabeth tied up and held hostage by Luke and learning that the General is Zoë's father, the Titan Atlas, Percy takes the sky from Artemis so she can fight against the Titan. Artemis engages Atlas and is able to trap him under the sky again, but not before he seriously wounds Zoë by pushing her off of a cliff. Thalia battles Luke, and he falls from the cliff, apparently dead. With the help of Mr Chase, who arrives in a biplane he has fitted with machine guns that fire celestial bronze bullets, they escape and travel to a nearby airfield in Artemis' silver chariot. Zoë dies shortly after landing and Artemis makes a constellation in her honour. The rest of the group then head for Mount Olympus.