Closed CircuitWho watches the watchmen? There’s still no satisfactory answer to that question come the end of John Crowley’s mystery thriller, but one things for sure – the watchmen have every angle covered… and they’ve got a zoom function.

CCTV cameras survey every inch of Borough Market in the fantastically tense opening sequence to Closed Circuit. Something’s wrong, but we’re not sure what. Crowley invites us to assess every face and gauge whether they’re a potential threat. Listen into their private conversations and make sure they’re not saying anything suspicious. There’s an unsettling edge to the voyeurism, but also an implied necessity – especially when we notice exactly what’s wrong with the scene, but by then it’s far too late.

Stylistically, it’s something you’ll wish Crowley would have returned to, because it’s easily the standout scene in a film that often feels uninspired. And thematically, it’s really interesting ground that’s being covered. We’ve been watching victims, not suspects. So where is the line? When do the costs to our privacy and civil liberty outweigh the merits? Who’s culpable when it goes too far, or goes badly wrong? But Steven Knight’s sidesteps those questions for the most part, and instead presents us with a mystery plot, which very quickly gives way to a breakneck thriller in which the watchmen presented are a near omnipotent force – unilaterally bad and never intending to be anything less.

Eric Bana – sporting a decidedly dodgy English accent – and Rebecca Hall play ex-lovers brought together on the defense team of the man accused of being responsible for the Borough Market terrorist attack, but it’s not long before the begin to suspect that a much larger conspiracy might be afoot. The mystery unravels in front of them with relative ease (save for a few crucial details left concealed for the final act), but they’re not the first to have started digging and it didn’t end well for those who went before them.

And then before you know it we’re in conventional thriller territory. There are foot chases, car crashes and tense meetings taking place all over (an admittedly well-shot and expertly employed) London. The dialogue trends towards the bland and expositional. It’s fine, but given the set-up and subject matter it could all be so much better.

Rebecca Hall delivers an expectedly strong performance, but she’s let down by a poorly-written relationship with Bana. He, on the other hand, loses his character almost entirely under the troublesome accent. There are nice supporting turns elsewhere, particularly from Riz Ahmed and Anne-Marie Duff, and to it’s credit the film does end up in a place that’s perversely satisfying from a narrative standpoint. Well, almost. There’s a final twist of sorts that undermines that too. For the story that the filmmakers appear to want to tell, that’s one circuit that probably should have stayed closed.