Unknown - SPOILERS

Dr Martin Harris (Liam Neeson) is traveling to Berlin with his wife Liz (January Jones) for a bio-medical conference. Martin is scheduled to give a presentation about his research as part of the event. After taking a taxi from the airport to their hotel, Dr Harris realizes that his briefcase was left behind. While his wife checks in at the reservation desk, he takes a taxi back to the airport to retrieve it. During the trip, the taxi driver swerves to avoid an accident and drives off the road into a river. Martin suffers a blow to the head during the crash and has to be pulled from the water by, Gina, the taxi driver. His heart stops but paramedics are able to revive him.



Martin awakens in the hospital to discover that he has been in a coma for four days. His memory is a little shakey, but remembers his name and a conference he's to be at. He fears his wife is worried and checks himself out against the advice of the attending physician. Martin goes to his hotel and sees his wife entering the ballroom for a dinner party. When he approaches her, she denies knowing him and insists that he is not her husband. Another man (Aiden Quinn) then appears at Liz's side claiming to be the real Dr Martin Harris. He has proper identification whereas Martin has none. Martin thinks some kind of sick joke is being played on him. After police and security remove him from the party, Martin watches as an Internet search turns up several pages which seem to indicate that the other man is the real Martin Harris.



A combination of clues and regained memories eventually leads Martin to understand the truth of the current situation. There is no Dr Martin Harris. Martin and Elizabeth are part of a group of hired assassins. They were using the fake "Dr and Mrs Harris" identities in order to get into the conference to steal valuable research from one of the other participants. When Martin disappeared for 4 days due to the car accident, another member of the team stepped in and took over the role of "Dr Harris" in order to complete the assignment. "Dr and Mrs Harris" are going to steal Dr Bessler's research on a groundbreaking new strain of corn and kill him in a fake terrorist attack.



Martin is ashamed of what he remembers about his past life and what he and his teammates planned to do that he decides to stop them. He goes to the hotel security office and warns them about the bomb that is planted in one of the rooms. As guests are evacuated from the hotel, Martin confronts the other Dr Harris, and as the two men are fighting, the bomb goes off. Liz is killed in the explosion and a large part of the hotel is damaged. Martin ends up killing the other "Dr Harris".



At a press conference several days later, Dr Bessler announces that he will not patent his valuable research on corn, but will instead share it with the world in hopes of wiping out hunger. Martin and Gina use the fake IDs and money that were inside his missing briefcase to begin new lives.