On holiday in Indonesia, hard-nosed French journalist Marie Lelay (Cécile de France) is caught in a devastating tsunami. Close to drowning, she has a near-death experience that convinces her there is an afterlife.
Putting her career on the line, she resolves to investigate life's greatest mystery and begins to write a book on the scientific evidence that supports her strange experience.
Meanwhile, in San Francisco, psychic George Lonegan (Matt Damon) is struggling to come to terms with his gift.
Having previously used his ability to talk to the dead for commercial gain, the - quite literally - haunted George was so disturbed by his experiences that he packed in the profession and became a factory worker. Meeting a young woman, Melanie ([Dallas Howard), at a cookery class, however, George is persuaded to help her contact a deceased family member.
In London, deprived 12-year-old twins Marcus and Jason (Frankie and George McLaren) live with their heroin-addicted mother. When Jason is killed in a tragic accident, Marcus is devastated by the loss and attempts to find someone who can talk to those on the other side.
As fate brings them together, the lives of these three individuals will intertwine with profound consequences.