Percy, expelled from six schools for being unable to control his temper, learns the truth from his mother that his father is the Greek god Poseidon, and is sent to Camp Half Blood where he is befriended by a satyr and the demigod daughter of Athena who join him in a journey to the Underworld to retrieve Zeus's lightning bolt and prevent a catastrophic war.

Orpheus, a mortal rock god, asks Persephone to help him get the love of his life, Eurydice, back from the underworld, and Persephone agrees to enlist Hades help after she is voted most dependable by her friends, a label she doesn't want to have.

All of Olympus--and the Underworld--are talking about the God of the Dead and the sprightly daughter of Demeter. But despite the rumors of their romance, Hades and Persephone have plenty to navigate on their own. Since coming to Olympus, Persephone has struggled to be the perfect maiden goddess. Her attraction to Hades has only complicated the intense burden of the gods' expectations. And after Apollo's assault, Persephone fears she can no longer...