Closed Circuit is a deft thinking man’s thriller from the team of producers behind Tinker, Taylor, Soldier, Spy. Clearly, they know intrigue, though Closed Circuit is less of a brain boggle than that 2011 Cold War chess game. It’s never a street brawl either, though plenty of blood is spilled (mostly off screen). Based on real events, the film opens with London rocked by a massive terrorist attack that kills over 100 innocents. The means of mayhem is nothing special — a truck full of explosives is parked in front of an open market and triggered by a suicide bomber — but what is special is the fact that the mastermind is so easily caught.

The rub comes during the trial. The Crown wants a closed hearing due to sensitive “secret evidence” that could put public safety at risk. At least, that’s the line being towed by the attorney general, played by a slimmed-down James Broadbent, who gives his character the air of an avuncular, creepy puppet master.

As the trial gears up, a nosy defense attorney (James Lowe) commits suicide by jumping from a tall building. His replacement attorneys don’t buy the unhappy gay story circulating in the rumor mill and begin to poke around, but they have other challenges to contend with. The married Martin (Eric Bana) and Claudia (Rebecca Hall) were romantically involved, which not only wrecked Martin’s marriage but, if it comes to light, could get them booted from the trial. To complicate matters even more, the two can’t communicate during the closed session segment of the trial and only Claudia, as the special advocate with classified clearance, can look at the secret evidence.

It sounds more convoluted on paper than it looks on screen. Director James Crowley (Boy A), artfully imbues tension and peril into every scene. When Claudia is presented the evidence by Nazrul (Riz Ahmed), a boyish agent with dangerously dark features, she questions how he got into her sealed office. He calmly tells her the door was open when he got there, but she knows that’s not true and from that moment on, both she and Martin know that MI5 is likely involved and that a cover-up or conspiracy could be in play.

Bana and Hall play off each other well, convincingly portraying their characters’ integrity as well as their introspect and resolve. You’re so ingrained into their thinking and plight that there are times, especially with Bana’s Martin, that you begin to question whether he’s gone over the top and fallen into pure paranoia. As with the Bourne films, there’s constant surveillance everywhere (Crowley uses the security cam POV a lot and it’s just one of many layered meanings within the film’s title), and the busy streets are forever a mecca for unassuming pedestrians and loiterers to leap out as would-be assassins.

Much to Crowley’s credit, the twists and turns are handled with sharp clarity even as the film clicks along, ever agile and sprite under the menacing pall. The editing is tight as are the bit players like Broadbent and Ahmed.

Anne-Marie Duff is also quite good as a transportation secretary, but the same can’t be said for Julia Stiles in the flimsy role of a New York Times reporter working the London desk. She further underscores the Bourne-like essence, though Closed Circuit stands on its own and rightfully so. Crowley has toiled at his craft for some time in relative obscurity — Closed Circuit could change all that. Let’s just hope Hollywood doesn’t change him.