Percy uses Hermes’s wind-filled thermos just before the lifeboat hits the sea, turning their fall into a fast escape from the Princess Andromeda. While they speed away, Percy and Annabeth try to send an Iris-message to Chiron so someone trustworthy will know about Luke’s ship, army, and Kronos’s remains. The connection is noisy and chaotic, but Chiron manages to warn them imperfectly before the message breaks apart.

The magical wind carries them all the way to Virginia Beach. At sea, Percy suddenly knows distances and exact coordinates by instinct, which Annabeth connects to Poseidon. When a coast guard boat starts chasing them, Annabeth directs Percy into Chesapeake Bay and then into a river, where the shift to fresh water weakens Percy’s sense of direction and leaves Annabeth to guide them to a hidden swamp shelter.

The shelter turns out to be an old half-blood safe house that Annabeth built long ago with Thalia and Luke. That discovery reminds Percy how deep Annabeth’s history with Luke runs, and Percy realizes he feels jealous. Percy and Annabeth discuss Luke’s easy escape from the ship and conclude he may have deliberately let them go so they would retrieve the Fleece for him; Annabeth also firmly rejects Luke’s claim that Thalia would have joined him. When Percy asks about Luke’s comment on Cyclopes, Annabeth starts to explain her distrust, but Tyson interrupts with a box of donuts from a suspicious shop nearby.

Percy, Annabeth, and Tyson investigate the isolated Monster Donut store in the woods, and Annabeth explains that some magically linked franchise chains are tied to monsters. Before she can explain further, a Hydra emerges, already tracking them from their campsite. Percy tries to fight it and cuts off one head, only to make the creature stronger when two heads grow back. Annabeth realizes they need fire to stop the regrowth, but without it the trio can only retreat while avoiding acid and trying not to make the Hydra multiply further.

As the Hydra closes in, Tyson protects Annabeth and Percy with brute force, buying them time. Then a steam-powered ironclad appears on the river and fires a cannon, blowing the Hydra apart. The ship is the CSS Birmingham, crewed by undead Confederate soldiers, and Clarisse stands aboard in Greek armor. She mocks Percy’s group for needing help, but orders them to come aboard, bringing Percy’s unauthorized mission into direct contact with the official quest.