Get the right conspiracy thriller - The Conversation, The Parallax View, Missing - and years later you're still thinking about it, scouring stories for subterfuge and then telling yourself not to be so paranoid. With Boy A and Intermission director John Crowley behind the lens, a screenplay by Dirty Pretty Things and Eastern Promises writer Steven Knight and an excellent cast, Closed Circuit looked like the most worthy of additions to the genre. Ironic, then, that a movie all about the pursuit of justice should fail to do right by you and its subject matter.

A truck bomb in London kills 120 people. A man is arrested in a dawn raid and charged with being a member of the terrorist cell. Six months later, following the suicide of the accused's original barrister, Martin Rose (Bana) is appointed as his new defence. Also working for the defence is a special advocate called Claudia Simmons-Howe (Hall) whose job is to handle the in camera sessions involving State secrets and who is forbidden from contact with Rose and vice versa. Rose and Simmons-Howe, however, have history and must decide whether professional pride or principles are more important - and how much they'd be willing to risk to get to the truth.

Closed Circuit should have been held in the same esteem as Edge of Darkness on the small screen and Defence of the Realm on the big one, but after an excellent opening - CCTV used to great effect - it begins to unravel. At 96 minutes the film is too short for the story it's trying to tell; the characters aren't developed enough to make you care and you find yourself looking for holes in the plot because you're not immersed enough in it. While there's the odd flash of class (Broadbent's turn as the Attorney General, in particular) films with far less assets at their disposal have managed to do far more. By the time the far-fetched and foot-to-the-floor ending arrives apathy has already had its day in court.

Let's hope that this case will be reopened as a six-part TV series at some stage.

Harry Guerin