Twelve-year-old Percy Jackson learns he is a demigod, the son of a mortal woman and Poseidon, god of the sea. His mother sends him to a summer camp for demigods where he and his new friends set out on a quest to prevent a war between the gods.

"The Underworld usually isn't really meant to be a fun place - but tell that to Hades! He loves the dark and the stinky smell of sulfur. However, there is one thing that Hades is not a fan of: dogs. And when Zeus and his fellow Olympians encounter Cerberus - a snarling, three-headed dog - Hades must conquer his fears and tame the hound so everyone can continue into the Underworld and deposit their Titan prisoner, Oceanus, back where he belongs!"--Information...

Terrified of being killed by one of his children, Kronos devours each of his offspring in turn. Only Zeus, the youngest, is saved. Though raised to enjoy a life of leisure, Zeus must fulfill his destiny and lead a new race of gods--and he must begin by destroying his own father.

When ten-year-old Zeus is kidnapped, he discovers he can defend himself with a magical thunderbolt.

After learning that he is the son of a mortal woman and Poseidon, god of the sea, twelve-year-old Percy is sent to a summer camp for demigods like himself, and joins his new friends on a quest to prevent a war between the gods.