Martin follows his wife inside a photography exhibiton museum, but notices that she is being followed by the hitman. Finally sensing his chance to get close to her, he confronts her about what has happened - she tells him that she was being made to say those things and to deny knowing him, and that he must go along with the plan or else she'll be in trouble. She kisses him and tells him to wait for her at the airport. He leaves before the hitman can catch him.
Meanwhile Jurgen has used his contact at the airport to find security photos that show Martin and his wife together. At his home he receives a call from Rodney Cole (Frank Langella), Martin's professor colleague, who tells him that he has been in Leipzig, but has trouble to pronounce the name. He tells Jurgen that he wants to meet him at his home and will be there shortly. Jurgen pieces together what has happened.
Martin gets to the airport with Gina, and correctly guesses the code to his briefcase in lost property. Inside are his passport with wads of cash ... and many more passports.
Rodney Cole arrives at Jurgen's apartment. Jurgen gives a clue that he knows what has happened. Rodney says that he needs to find out everything, and that he should have ran for it. Jurgen pours a small packet that looks like sugar into his tea. He starts to convulse -- it was cyanide. He dies bravely in Rodney's arms.
Martin gives Gina money to start her new life. She returns his watch. He decides to wait in the airport as she catches a cab. She watches as he meets with Rodney Cole and is escorted to a black van - then suddenly the hitman gets out and bundles him into the back.
Gina panicks and steals the cab, and follows the van. Martin is taken to an upper level of an empty car park. Rodney reveals the twist -- Martin is a professional assassin. His wife is just his partner in the hit, they make a good team. They have been planning this hit for months, but when he hit his head he suddenly began to believe his own lies and fake backstory. The other Martin Harris was his understudy. Unfortunately, Martin is now expendable and must die.
The hitman beats him up a little and prepares to shoot him in the head, when Gina roars onto the scene and flattens the hitman. She reverses, and hits him again against the van -- this time pushing the van, with Rodney inside, off the top level. It explodes on impact. with the ground below
Martin remembers what happened - 3 months earlier he had been to Berlin with Liz, his partner/wife, to plant a bomb in the hotel suite. The target is the biochemist and not the Saudi Prince - yet others will think it was a terrorist plot by extremists if he is involved.
At a reception for the conference guests, the biochemist is invited into the hotel suite and Liz plants a bug in his laptop case that copies the files from the harddrive - using passwords from the book. Martin and Gina are stopped by hotel security. He convinces the security chief to review tapes from 3 months ago - and sure enough a still of Martin with his wife is on file. They evacuate the building.
Martin breaks free from the guards to find the target and his stooge. Meanwhile Liz works to defuse the bomb that is not needed anymore. Martin B finds the biochemist, but is stopped by Martin. The bomb explodes, Liz is vaporized, and the building starts to fall apart. The biocemist gets away. Both Martins face off. Liam Neeson is knocked on the head, and remembers his training again - he then kills the bad guy. Gina watches, unsure what will happen - but the nice, new, Martin persona wins.
Later, in a televised conference, the Prince and the biochemist announce their new invention - a better strain of corn that can survive in harsh conditions and will bring help to the world's poorest. Shares in other foodstuffs drop heavily. Martin has made a new passport for Gina, and decided to call himself Mr Henry Taylor (good surname) in his own. They leave together, happy.