After a past school year for once without incident, Percy is eager to return to summer camp for demigods. An unpleasant surprise awaits: the Thalia tree, which will protect the camp from intrusion of monsters, was poisoned. Only the legendary golden fleece could save this haven of an inevitable destruction. But obtaining a permit to conduct a new quest is far from assured for Percy and the dangers are many on the way to the sea monsters. In this second volume, the reader gladly continue reading the adventures of the young Percy always friendly, friendly and brave. The author continues to immerse in Greek mythology the "sauce" fantasy.