Percy Jackson begins his first morning as a senior at Alternative High in Queens, frustrated that he must return to school after years of demigod battles and a lost junior year caused by magical amnesia. He is determined to graduate on time so he can attend New Rome University with Annabeth, but he is already overwhelmed by classes, textbooks, and the pressure of making up credits.

After two classes, Percy is called to the counselor’s office. The counselor, Eudora, first appears ordinary, but Percy notices strange signs: salt water, oyster-like hair, and a jellyfish-like dress. Percy realizes the Mist has hidden her true form and identifies her as a Nereid, a sea spirit sent by Poseidon.

Eudora explains that Percy’s mortal college requirements are manageable, but New Rome University also requires three divine recommendation letters from three different gods. Percy reacts with anger and disbelief because the requirement means more work for the gods after everything Percy has already done for them. Eudora becomes distressed, flooding the office as Percy realizes the letters likely require new quests.

Percy asks why Poseidon did not explain this himself. Eudora receives a shell-phone call from Poseidon, then tells Percy that Poseidon agrees and will explain in person immediately. Before Percy can return to class, the water beneath him becomes a whirlpool, the floor dissolves, and Percy is flushed away toward his father.