Both the marketing and the USP of this movie seemed to be about excess surveillance, but there was a strange lack of it in the film except as a plot device.

It's also much more of a potboiler than a movie with any kind of message – you just know at least one twist the writer and director hopes you'll find jaw-dropping is coming some time, and you're not disappointed (or you are, as the case may be).

After a terrorist bombing at a crowded London market, a suspect is nabbed and straight away the persecution proceeds under the auspices of anti-terrorist legislation that has the power to keep critical evidence secret for reasons of national security.

Lawyers Charlie (Bana) and Claudia (Hall) are ex lovers finding themselves in the uncomfortable position of being on the same team. Not only does knowing each other the way they do threaten to compromise their objectivity, there's also a cloud of mystery over the case after the previous public defender died in an apparent suicide.

The government is pushing for a strong, swift conviction but in true legal thriller fashion, things don't add up. Before long Charlie and Claudia find themselves followed, the sense of paranoia and menace growing until it turns from a legal drama to an all-out chase thriller complete with government assassins in tow.

It needed a bit more originality to be a thriller, and it needed less running, shouting and Hollywood-style thrills if it had something legitimate to say about the modern justice system.