When Thalia’s tree is mysteriously poisoned, the magical borders of Camp Half-Blood begin to fail. Now Percy and his friends have just days to find the only magic item powerful to save the camp before it is overrun by monsters. The catch: they must sail into the Sea of Monsters to find it. Along the way, Percy must stage a daring rescue operation to save his old friend Grover, and he learns a terrible secret about his own family, making him question whether being the son of Poseidon is an honor or a curse.
Libro chiaramente di transizione per aggiungere qualche personaggio (interessantissimo, sia chiaro) e far evolvere la situazione lasciata in sospeso dal primo titolo.
