I admit that this isn't a great movie, but neither is it a bad one. This is in spite of the fact that the plot, which was adapted from the novel, "Out of My Head" by Didier Van Cauwelaert, seems to be constructed using plot points taken from several other recent movies. Nevertheless, it remains a highly entertaining movie, and it is made all the more pleasing because of its excellent cast of actors and an interesting plot twist at the end. 

The exceptional casting besides Neeson includes January Jones from the AMC television series, "Mad Men." She initially plays his affectionate wife, but she quickly turns into the ice princess we are more used to seeing on television. Diane Kruger portrays a spunky waitress and the former cab driver who rescues him and stays around to provide further aid. Aiden Quinn portrays Dr. Harris' seeming doppelgänger, while the outstanding German actor Bruno Ganz portrays an ex-Stasi agent who provides Dr. Harris with critical help. Arriving late to the story is Frank Langella as a long time friend of Dr. Harris who may not be who he seems. Say what you will about this movie, but this is certainly an A list of fine actors. 

Liam Neeson is immensely appealing as a middle aged, thinking man's action hero with his impressive physique and wonderful voice. Let's face it: the guy does have a presence and gravitas in spades, which he uses to great effect as an American botanist whose mind may or may not be playing tricks on him after an accident. 

Dr. Harris and his wife, Elizabeth (January Jones), have just arrived in Berlin for a symposium. Everything seems to be perfect as the obviously affectionate couple get out of a cab to check into a plush hotel in Berlin. Suddenly, Dr. Harris is shocked to notice that his briefcase with all of his notes and identification papers has been left back at the airport. He grabs the first cab he can to race back to the airport, but on the way the cab is involved in a multiple vehicle accident and ends up crashing through the bridge railing to land in the river beneath. 

Knocked unconscious, Harris is facing certain death when by luck and by spunk, his cab driver, who later turns out to be Gina (Diana Kruger), a Bosnian illegal immigrant, breaks the rear window of the cab and hauls him to safety before the cab sinks to the bottom of the river. 

Days later he wakes up in a German hospital and inquires if his wife has been in to see him. She hasn't. Much to the chagrin of his attending physician and the head nurse, he leaves the hospital and races back to the hotel to see his wife, who convincingly pretends not to know him. Worse still, she introduces her husband, Martin (Aiden Quinn), who has the exact same identification papers and romantic picture in his wallet as what Martin used to have.

Martin heads over to the university to meet with the German botanist (Sebastian Koch), who was to be his contact man and an honoree at the convention hosted by a Saudi prince (Mido Hamada). Unfortunately, the two had never met, so he can't provide any positive verification. A visit to the taxi cab company proves to be equally fruitless, for Gina had been fired for getting in the accident and wrecking her cab. Martin does learn that she is working as a waitress at a local diner. 

Then he returns to the hospital, where deadly danger awaits. He doesn't know who he is anymore, but someone wants to kill him for whoever he used to be... 113 minutes, and rated PG-13 for some intense sequences of violence, action, and brief sexual content.