Unknown is a 2011 film (there is another with the same title that I have yet to see, but which sounds good) starring Liam Neeson and January Jones. It opens with the pair of them arriving in a snowy Berlin. Dr Martin Harris, along with his wife, scheduled to attend a high profile academic conference on biotechnology. As they come to check in, one of their suitcases goes missing. Neeson hails a cab driven by a young woman and heads back for the airport.
However, the car crashes, and although the driver saves Neeson, he winds up in hospital and is out of it for four days. When he wakes up, he finds his wife has not asked after him. He goes back to the hotel, but his wife denies all knowledge of him - and is accompanied by another man, who says he is Dr Martin Harris. A quick internet search reveals the other man's face on the university website...
It's a wonderful premise, and the action seldom flags from that point. Neeson is a big man, but he also has a vulnerable quality that makes him a very appealing hero. But - is he a hero? What is going on? You do have to sympathise with someone who thinks he is married to January Jones and then finds she blanks him! Is she being put under pressure or blackmailed, or is there some other reason for her behaviour?
Of course, a story like this depends very heavily on the quality of the explanation for the puzzle. So often the answer is a let-down. But in my opinion, the story was well-structured, and the explanation worked for me. I was also reminded what a marvellous city Berlin is - I last went there when I was a student, and the Wall was still up. I was staying in a flat near the Wall and remember hearing shots fired one evening when we were having a meal. Must get back there, and see how it has changed. Unknown certainly encouraged me to return, though not, I hope, with the results encountered by Liam Neeson... There was one aspect which I felt implausible, but can't mention for fear of spoilers. Overall, though, a very gripping and well-made film, and I certainly have no hesitation in recommending it.