After spending four days in a coma Martin Harris awakes in a Berlin hospital to find that the rest of the world has developed a strange case of amnesia. Nobody recognises him and even his own wife shuns him.

Because he's a bit of a crusty old dullard these days it's easy to forget just how good Harrison Ford was back in his middle age: an acceptable figure of decency and a human sized action hero.

We've been in need of a new Harrison Ford for some time and by a strange twist it seems that its going to be the Old Liam Neeson.

He may be pushing 60 but he can play mid-40s convincingly and since the out-of-the-blue success of revenge thriller Taken he has risen to a level of genuine open-a-film stardom that he had never quite attained before.

It's a level which he should consolidate here with his very own take on the American lost and abandoned in a duplicitous foreign capital theme that ford successfully exploited in Frantic.

For the first hour Neeson wanders around in a daze but in the second he takes up arms against his problems. It seems odd that this respectable scientist should suddenly prove adept at fighting and car chasing but when you have someone as imposing as Neeson in the role it largely overrides such objections.

The basic plot is preposterous but not insultingly so and the final reveal is very satisfying – you don't see it coming and it is a nice fit.

There's nothing exceptional here but it's well presented and the service is top notch. Most everything is crafted to move the plot forward but the film still finds a bit time for Bruno Ganz and Frank Langella to show their qualities.

The pounding light and sound diversions to gawp at, mean here's an entertaining night out at the cinema that a grown up could enjoy with dignity intact.

Unknown (15)

Director: Jaume Collet-Serra

With: Liam Neeson, Diane Kruger, January Jones, Bruno Ganz, Aiden Quinn and Frank Langella

Length: 113 mins

***