Neeson plays Dr. Martin Harris who, with his wife Liz (January Jones), arrives in Berlin to attend a biotechnology summit. Harris jumps a cab on his own to retrieve a forgotten briefcase from the airport, but is involved in an accident en route. Waking up from a coma in hospital four days later, Harris returns to the hotel he and his wife had checked into, only to find his wife doesn't know him and another man (Aidan Quinn) claiming to be Dr. Martin Harris.
When at its weakest, Unknown presents ridiculous, fairly mindless action; when at its best, it is a psychological thriller that shares more than a little genetic material with the Bourne films in a very positive way.
The first half an hour is straightforward enough: the pace is kept high, the cerebral challenge low, and the ludicrous premise firmly established. As the film progresses however, the intrigue is ramped up further and further, whilst the pace maintains energy but slows and steadies to allow director Jaume Collet-Serra to craft where the story goes and when. By the time Bruno Ganz's ex-Stasi officer is introduced, you're in the middle of a very satisfying thriller indeed. A scene between Ganz and Frank Langella is the film's high point - tense and understated, with the psychological chicanery at its height.
Its a shame that, as things head into the final act and the majority of the questions posed have been answered, the more ridiculous side of things becomes dominant once again. What you end up with is a cinematic sandwich - the opening and closing thirds providing ludicrous action, enjoyable but never more than just good, with the middle third a slice of satisfyingly excellent psychological thriller.
Neeson is dependably strong in a role which, for the most part, requires him to frown a lot in either confusion or anger; in less skilled hands, the part would be entirely bland and the film limp, but with Neeson at the helm, this is never the case. Support from Ganz and Langella is convincing, and Diane Kruger also does well. At the opposite end of the scale is January Jones however, who saps any scene she is in of either tension or credibility. Jones is wooden to the point of being cringe-worthy, failing to imbue Liz Harris with either emotion or motivation at any point. Thankfully she is largely sidelined by the far superior Kruger for most of the film, barely featuring in the middle third.
All things considered, Unknown is uneven, but still manages to impress. Without Neeson as the lead, this could have been much more forgettable, which is to his credit. Collet-Serra's direction is skilled, but if the whole film had been more like the middle segment Unknown could have been excellent. As it is, what we have is a worthwhile and enjoyable action thriller.