In an interview where the conversation turned to his wife’s (Natasha Richardson) untimely death, Liam Neeson explained how he threw himself into his work to cope. Though bringing to life the plot of Unknown must have had its hard moments – it revolves around a man whose wife is lost to him, after all – Neeson proves that this statement was not over-the-top, racing around Paris and Berlin with a zeal not commonly found in the average fifty-eight year old.

Dr Martin Harris (Neeson) is a biologist set to lecture in Berlin, when an unexpected taxi ride from Bosnian immigrant (Kruger) ends with the taxi in a river and Neeson with a pretty serious bump on the noggin. Waking up in a German hospital, he attempts to get back to beautiful wife Elizabeth (Jones), only to discover that another man has assumed his identity, and his wife and the rest of the world seem to be swallowing the lie. The rest of the film follows his struggle to reclaim his identity, appealing to a nonplussed Elizabeth and escaping from a cold-blooded (and bespectacled) killer with the help of plucky immigrant Gina. Is he mistaken in thinking he’s the respectable doctor? Or are darker forces at work?

The plot sounds a little predictable, but you’ll have to trust me when I promise that there is a big enough twist at the end to elevate it out of the usual amnesiac genre, and to reveal any more would ruin a movie that rests entirely on its premise.

There are some disgustingly tense action scenes: a car chase where the taxi, driven by Gina, is reversing down a pavement, nose to nose with a black Hummer is nail-biting, and it is a pleasure to see action men that are not of the Kellan Lutz variety. Liam Neeson looks every inch his fifty eight years, settling into his American accent more as the movie progresses, and providing a little authenticity to a bog-standard ‘man in identity crisis’ role. In-fact Neeson is underused, if such a thing is possible of a man that is in every scene, adding to a few elements that let Unknown down somewhat.

Ernst Jurgen (Bruno Ganz) is perfect as the ex-Stazi who retains a fierce moral code, and Kruger hides her beauty just enough to convince as a poor Bosnian immigrant (even though the accent is a little dicey), but January Jones strays not at all from her buttoned-up role in Mad Men, leading one to wonder if she can convey any other emotion than icily detached.

The reason for Dr Harris’ ostracization is surely the most important plot point, but one gets the feeling that shiny loud noises and stuff appeal far more than explaining biological crop patterns, leaving the ending to be shouted over a backdrop of a big explosion. Still, considering the ridiculousness of most action-film plots, this is somewhat of a moot point, and with some unusual cinematography, mostly solid performances, and an excellent premise, Unknown can rest in knowing it has done what it set out to do.