The Gathering: Book 1 of the Lia Fail Chronicles by S.L. Dearing
Thirteen years after the last world war, the village of Lia Fail sits peacefully above the Hollywood Reservoir in the Santa Monica Mountains. The village is making ready for the fall Gathering, where the other colonies from various parts of what was once Southern California visit for ten days of fun and reminiscence. What begins as a normal Gathering, soon changes as the people of Lia Fail begin to see magic around them. Then they receive news of a horrific massacre and face a nightmare as a dark evil descends on the tranquil village. Alia Stark, the queen of Lia Fail, must face this evil along side her oldest and dearest friends as well as an incredible new ally as the fate of her people and the lives of her children rest in her hands. Will her new magic be strong enough to save those she loves the most?