Finn and Sawyer Westin, and their families and friends, survived the flooding after the global disaster and successfully defended their island refuge. The island was secure, but the world outside was not, and the needs of the innocent pull them into danger. The foreign nation that caused the disaster has invaded American soil and is spreading suffering in their wake. As the Westin enclave adds rescued survivors, they encounter others fighting back, including military resistance forces who are badly outgunned. The island group possesses critical resources and skills that put them in the center of the struggle against the powerful foreign invaders. But can Finn, Sawyer, Martina, and young Aurora meet the challenge and save a nation on its knees?