At "Area X", a government facility on the southern coast of the US, Lena, a cellular-biology professor and former soldier, is in quarantine. She undergoes a debriefing about a four month expedition into an anomalous iridescent electromagnetic field called "the Shimmer" from which she and her husband Kane are the only survivors.In flashback, Lena's husband, an Army Special Forces soldier, appears in their home after having gone missing on a mission nearly a year ago. He remembers nothing of that time and suddenly becomes very ill. A government security force intercepts Kane's ambulance and transports him and Lena to Area X, near where the Shimmer had begun to spread three years earlier. A psychologist, Dr. Ventress, explains that military teams, including Kane's, have ventured into the Shimmer to attempt to reach the lighthouse where the phenomenon first appeared. Kane is the only person to have ever returned from an expedition. Lena volunteers to join Ventress on a research expedition consisting of two scientists, Josie and Cassie, and a paramedic, Anya.