In the late 1950s, the FBI planted a rudimentary listening device behind the radiator in a Michigan Avenue tailor shop often frequented by Chicago mob bosses, and thus gathered a wealth of information about notorious chiefs such as Sam Giancana and Anthony "Joe Batters" Accardo. The Chicago-born writer-director Graham Moore has told interviewers that historical nugget was the seed for The Outfit, a taut, claustrophobically gripping, beautifully acted period piece set entirely in the rooms of a neighborhood tailor shop frequented by Chicago mobsters and their associates. You gotta love that.

The Outfit has some similarities to films such as Deathtrap and Sleuth and Kubrick's The Killing, but it also reminded me of Reservoir Dogs in that there's been an offscreen shooting, a man is bleeding out and can't be taken to a hospital, every indication says there's a rat within the ranks - and the hot-tempered son of a crew chief believes when Daddy gets here, he'll know what to do.

We already know Moore, the Academy Award-winning screenwriter of The Imitation Game, has a keen ear for dialogue, and his feature film directorial debut showcases his deft ability to keep the action fluid and visually interesting in a static setting. (The cinematography by Dick Pope, the music from the ubiquitous Alexandre Desplat, and the sepia-toned lighting and the striking production design greatly enhance the viewing experience.)

Oscar winner Mark Rylance delivers a low-key, slow-boil performance as Leonard, an unassuming but intensely focused and prideful Saville Row tailor who says he relocated to Chicago because, thanks to James Dean.

But don't call Leonard a "tailor." According to Leonard, any fool with a needle and thread can learn to be a tailor in 10 minutes. Tailors make one item of clothing. Leonard is a "cutter," i.e., he marks and cuts and shapes and trims the entire ensemble, and it takes decades to perfect the craft. Got it?

(This is not throwaway information; it's an indication Leonard is a serious person, even though he's virtually invisible to the mobsters who regularly shuffle in, talking tough in sometimes wobbly Chicago accents and dropping off and picking up thick envelopes with mysterious markings and, oh yeah, getting fitted for suits as well.)

On a cold night in Chicago, the flashy, hot-tempered and not particularly bright Richie (Dylan O'Brien), whose father is a longtime mob boss, comes banging on the door alongside the more cunning and ruthless family lieutenant, Francis (Johnny Flynn). Richie has been shot in the gut after an ambush by a rival crew, and he's losing a lot of blood - but hospitals are not an option, and it will take too long for a shady doctor to be summoned, so it's up to Leonard to stitch up Richie with a needle and thread, and yes, it's as gruesome to witness as you might imagine.

Leonard wants nothing more than for everyone to clear out - he'll never say a word, of course - but instead, his shop becomes a way station for various comings and goings, as Richie plots his revenge, Francis makes some moves to advance in the ranks and there's talk of someone within the organization tipping off the feds.

Among the visitors are Richie's father, the intimidating mob boss Roy Boyle (Simon Russell Beale), and Leonard's bright-eyed receptionist, Mable (Zoey Deutch), who is like a daughter to Leonard and may or may not be mixed up with someone who has been in this room tonight.

The Outfit keeps us guessing throughout as to who is the "rat" and why said rat would be such a rat as to rat out the type of people who believe the only good rat is a dead rat. Rylance, dialing it down about one million percent from his irritatingly over-the-top histrionics in Don't Look Up, is back in prime form, conveying so much with just a glimmer in his eyes or a deadpan line delivery, leaving us guessing until the very end about Leonard's true motivations.

For a film set almost entirely indoors, The Outfit always seems connected to that outside world, and we believe the lives these characters have lived out there. Some will live to see another day; others might not be so fortunate. Writer-director Moore sets up the chess board in masterful fashion, and our only job is to sit back and enjoy how the strategies play out.

The Outfit

Three stars

Mark Rylance, Zoey Deutch and Dylan O'Brien

Graham Moore

R for some bloody violence, and language throughout