The film moves back and forth between three stories:
- George Lonegan (Matt Damon) is a factory worker in San Francisco, who has the ability to communicate with the dead loved ones of the people he touches. He considers this ability a curse and he is trying to live a normal life, despite being constantly urged by his brother Billy (Jay Mohr) to make money with his ability. George takes a cooking class where he meets Melanie (Bryce Dallas Howard). Melanie comes to his place for dinner and, after learning about his ability, convinces George to give her a reading despite his hesitations. However, after George relays a message from Melanie's dead father (apologizing for what he did to her in the past), Melanie becomes so upset that she leaves George's place and never returns to the cooking class. Later, George is laid off from his job and Billy presses harder for George to use his ability for monetary gain (even getting an office for the business). However, George instead decides to leave San Francisco and leaves for London to visit the home of Charles Dickens (who he's a fan of).
- Marie Lelay (Cécile de France) is a French journalist who has a near-death experience after she is knocked unconscious during a tsunami. This results in her being obsessed with the existence of the "hereafter" and visits an expert on the subject in Switzerland before deciding to write a book on her experience. Even though her publisher turns down the book, he later refers her to another publisher who decides to publish the book and invites her to London for a reading.
- Marcus and Jason (Frankie and George McLaren) are two London brothers, who rely on each other as they live with their substance abused mother. Jason is killed when he is run over trying to run away from muggers. Marcus is placed into foster care, while his mother goes to rehab. Marcus grieves deeply for Jason and keeps desperately trying to contact him, though all the "experts" he visits turn out to be obvious frauds. One day Marcus is about to enter the subway and his hat (which used to belong to Jason) blows off his head. This causes him to miss the subway, which subsequently explodes in a terrorist attack.
The three stories come together at the end:
George sees a sign at Charles Dickens house advertising a reading of one of Dicken's novels by Derek Jacobi. George attends the reading and afterwards he comes across Marie doing her reading. He is intrigued by her experience and gets a copy of her book signed. Before he could talk to her any further, George is approached by Marcus, who recognized him from his old website. George refuses to give Marcus a reading and goes back to talk to Marie, but she had left. Marcus follows George back to his hotel and stands outside until George finally agrees to give the reading, which finally gives Marcus the closure to move on. In return, Marcus locates Marie's hotel for George and George leaves her a letter. They arrange to meet and when Marie shows up George has a vision of the two of them kissing, which gives him the confidence to invite her to his table.