Carrie Mathison, a CIA operations officer, is on probation after carrying out an unauthorized operation in Iraq. As a result, she has been reassigned to the Counter terrorism center. Whilst in Iraq, she was warned that an American prisoner had been turned by Al-Qaeda. When Nicholas Brody, a U.S. Marine Sergeant, is rescued after being held hostage since 2003, she suspects that he is the one. While Brody is received home as a war hero, Carrie goes to any lengths necessary to catch him out.

Several characters who are each at critical stages of their lives are strangely impelled towards an uncharted lake in the middle of the desert where they all have the opportunity to save each other.

In Los Angeles, Henry is a veterinarian whose fiancée Kate dies in an accident on the day they're to marry. Worried that Henry has closed off his social life, his sister suggests he use a psychic to contact Kate, lay to rest unresolved feelings, and live more fully. He tries it, though he doesn't believe in it. Nothing happens, so his sister gives Ashley, the psychic, Kate's diary. Now she's able to convince Henry she's in contact with Kate and start the therapy. Two things happen: they find themselves attracted to each other, and Kate's ghost, who also has some unresolved issues, returns to stop this budding romance.