Oceanstar and the Olympians: The Lightning Thief

Twelve-year-old Ocean has never been allowed to stay in a group of rogues longer than, well, a moon. And half the time, it isn't even his fault for getting kicked out. With his mother mated to a foxhearted former kittypet and left behind in one of the groups he's been expelled from, he really has no choice but to wander.
But when a terrifying group leader becomes a terrifying monster, Ocean follows his mentor's instructions to the letter (for the first and last time) and flees for his life, towards the territory of the fabled warrior Clans, who worship long-dead cats and eat trespassers for breakfast. There he comes across HalfClan, a neutral camp for hunted cats, and finds out that there's so much more to the story.
Arrow, his favorite mentor in the group, is really Chironstar, leader of HalfClan. The warriors in the Clan are children of the very gods the Clans worship. And the new leader of what was once one of the three most powerful Clans is Ocean himself-and as the only member of his Clan left, he has to find Zeus-star's lost lightning bolt and return it before the Clans descend into war.
Given a warrior name and accompanied by his best friend, Leafheart of PanClan, and a sharp-witted she-cat who seems to sort-of hate his guts, Flarestrike from AthenaClan, he'll have to venture outside of the the known territory's and into the realm of the gods.
And that's not even counting the weird dreams....

[Note: Cats have much longer lifespans in this story, which is why I'm using years instead of moons. The Olympian Clans have about the same lifespan as a human, and the gods are immortal as always]