"Closed Circuit," starring Eric Bana and Rebecca Hall as a pair of sleek English defense attorneys who make those Old Bailey wigs look positively haute, opens with security-camera screens, first four, then eight, then 12, then 15, dispassionately recording street activity and anonymous passers-by in London's Borough Market neighborhood. A truck appears on one of the screens. The music signals trouble. A bomb explodes. More than 100 people die.
The rest of this confidently mounted exercise in omnipresent insecurity concerns the accused Muslim terrorist, who has ties to an earlier bombing in Munich, and the lawyers assigned to defend the apparently indefensible. There is, of course, a conspiracy afoot. If there weren't, you wouldn't be here, in paragraph two of a review of a British paranoia thriller.
As spun by screenwriter Steven Knight, who wrote the very good "Dirty Pretty Things" and "Eastern Promises," that conspiracy comes with a certain air of familiarity and a few plot holes. The thing about plot holes is that they're a pretty dull discussion point, because they involve what's missing, not what's there. Directed unfussily and well by John Crowley, "Closed Circuit" has enough on the ball in terms of atmosphere and crafty performances to take your mind off the gaps in logic.
The serious point inside this semiserious diversion is this: What happens behind locked doors, in the name of national security, has a way of giving character actors such as Jim Broadbent (as the attorney general) and Ciaran Hinds (as the protagonist's faithful sounding board) reasons to lower their voices lest someone overhear what they're muttering about.
The suspected bomber, a haunted presence in the hands of actor Denis Moschitto, acquires not one but two defenders. Bana plays Martin Rose, who works with his client in a closely watched public trial. But the state, Rose is told, has unearthed evidence so sensitive it must be revealed only in private, and for this separate trial, special advocate Claudia Simmons-Howe, played by Hall, is assigned to defend the bomber.
Rose and Simmons-Howe were lovers once and therefore are ineligible to proceed with their state-appointed duties. They proceed anyway, hoping to keep their past liaison a secret.
The movie builds its case on vignettes designed to unsettle without being too crushingly obvious about it. To wit: Hall's character, at home, alone, spies a book slightly askew on her shelf, indicating the recent presence of an intruder likely armed with sophisticated bugging equipment.
Meanwhile in a wittily realized parallel, Bana's character steps into the same London taxi twice (or maybe more often; he'll never know) in an improbably brief time span. "We're being managed," he tells his former lover. It's so much nicer than saying someone's on your tail.
Yes, there are holes where better bits of plot wouldn't have hurt. Early on, when "Closed Circuit" establishes the mysterious suicide of Rose's predecessor, the arrows point in too predictable a direction. And late in the game, after all sorts of threatened or actual violence and an hour of their every word and movement being tracked, there's a scene in Rose's apartment where the characters temporarily forget all that, simply because the story requires it.
The satisfactions of the film are in seeing what a screen full of excellent players can do to steer you around the holes. Bana never quite seems enough to anchor a picture for me; all the same, he acquits himself sharply here. And Hall is one of the best actors in contemporary movies, able to leap past horsy expositional monologues in a single bound and humanize a forbidding character.
The BBC and Channel 4 have excelled at this sort of narrative labyrinth for decades, and director Crowley consciously echoes certain American conspiracy thrillers of the 1970s. The difference here, mainly, is the overlay of insidious technology. It's frankly hard for filmmakers to get audiences to care about surveillance abuses these days. Young and even middle-aged audiences may be too busy being ad-targeted by Facebook to listen to screenwriter Knight bemoan the death of privacy.
Simpler and less nuanced than "Tinker Tailor Soldier Spy," "Closed Circuit" (drab title) keeps its head down and does its job like a reliable midlevel secret agent.