Percy, Clarisse, and Grover reach the cave entrance just as Polyphemus captures invisible Annabeth and drops her hard onto the rocks. Realizing Annabeth is badly hurt, Percy distracts the Cyclops while Clarisse and Grover attack from the sides. Their coordinated assault slows Polyphemus but cannot stop him, so Percy orders a retreat toward the rope bridge while Grover carries Annabeth to safety.

At the chasm, Grover and Percy cut the bridge in hopes of dropping Polyphemus, but the plan fails when the Cyclops ends up on their side anyway. After Polyphemus swats Clarisse and Grover aside, Percy attacks in a burst of rage and manages to knock the monster down, leaving Riptide poised over Polyphemus's eye. Percy hesitates because Polyphemus's fear reminds Percy of Tyson, and Percy cannot bring himself to kill a fellow son of Poseidon in cold blood. Percy accepts Polyphemus's false surrender, and Polyphemus immediately betrays Percy and nearly devours him.

Tyson suddenly reappears and saves Percy by hurling a huge rock into Polyphemus's throat, knocking the Cyclops into the chasm. Tyson explains that Rainbow the hippocampus rescued him from the wreck of the CSS Birmingham, and the two have been searching for Percy ever since. Seeing Annabeth's condition, Percy asks Tyson to retrieve the Golden Fleece. Because the sheep accept Tyson, Tyson removes the Fleece from the tree and throws it to Percy, who lays it over Annabeth. The Fleece heals Annabeth enough to wake her, though Clarisse quickly realizes Annabeth still has broken ribs.

With the sheep growing restless, Percy has Tyson lure them away so the group can escape. Clarisse carries Annabeth to the beach while Percy summons the Queen Anne's Revenge across the water. Tyson rejoins them, and Percy believes the sea will let them reach the ship safely. Just as the group begins wading out, however, Polyphemus appears again, bruised but alive, charging after them with two boulders in his hands.