The fifth Secret World Chronicle novel brings the metahero conflict to another turning point as ECHO and its allies face the consequences of the long war against the Thulians. Mercedes Lackey, Cody Martin, Dennis Lee, and Veronica Giguere continue the shared saga of people with extraordinary powers who must decide how to use them while protecting a world under threat. The official author page and publisher listing identify Avalanche as Book 5; read it after Collision.