The fourth season picks up right where we left off. Clarke has just learned the human race is doomed to face an unbeatable enemy. Alie was telling the truth. The remaining nuclear reactors on Earth are melting and will set the atmosphere on fire. Can our heroes find hope knowing the end is inevitable? Will they spend their remaining days trying to survive? Or will they use their limited time to finally live? The stakes have never been higher, alliances are breaking, and the world is about to collapse. Civility has no place at the end of the world and there's no telling what lengths our heroes can and will go to in order to survive.