At 11:49pm the world ends, leaving lovers Bea and Evian alone on their island vacation forever. Bea worries obsessively over their survival, and Evian's overall calmness. The weirder things become on the island, the more convinced she becomes that Evian is keeping a dark secret. This culminates in a fight over dinner where Bea is stabbed, only to wake up again the following day. The lovers fall into a cycle of lies, death, and distrust, but with the island impacting her memories and sanity alike, Bea struggles to piece together all that has happened. The more Bea tries to discover the truth, the more the world around them unravels. After a second death at Evian's hands she wakes up as a captive underneath the vacation home where she continues to spiral in her isolation. She eventually plays along and pretends that everything is fine long enough for Evian to free her, only to kill Evian in an attempt to level the playing field. She cleans up the body only to wonder how much of her perception of events is true, suddenly worried that Evian will not wake up as she has. The conclusion of the book sees Bea on the island during a storm, resigned to the implied fate of their purgatory dissolving into nothing around them, still hoping for her love to wake.The overarching themes of the book are coping mechanisms in the wake of loss, the importance of communication in a relationship, and how human perception can shape our viewpoint of the world.