“Free Fire” is the Boston crime-movie version of an SAT math problem. Two illegal arms merchants, two IRA soldiers, one middleman, one middle-woman, and two pairs of hired mooks gather in an abandoned factory for a late-night gun deal. If there are five crates of assault rifles, 10 pistols, and 4,287 rounds of ammunition — and x = additional gunmen of unknown provenance — how many tetchy insults will it take before the deal goes south and the shooting begins? Who will survive? How many Boston accents will be tortured in the process?
You have 90 minutes.
Because “Free Fire” is a essentially a comedy of bad manners — a bedroom farce that only happens to take place in a warehouse, with volleys of gunfire rather than slammings of doors — it’s a highly enjoyable 90 minutes, especially if your tastes run to the violent, the absurd, and the violently absurd.
The comedy is almost entirely in the characterizations and their collisions, brought to life by a cast that happily stoops to the occasion. “Free Fire” takes place in the early 1970s for no reason other than that the clothes were funnier then, the Troubles were still plaguing Northern Ireland, and the filmmakers can use John Denver songs on the soundtrack. Chris (Cillian Murphy) is the IRA man in from across the pond to buy the guns, a sharp, battle-tested player. Frank (Michael Smiley), older and blustery, is the local son of the ould sod who’s connecting Chris to the middlemen.
Vernon (a resplendent Sharlto Copley) and Martin (Babou Ceesay) are the arms dealers, the former South African, vain, and quick to take offense, the latter phlegmatic and African-American. (“He was a Black Panther, but it didn’t work out,” notes one observer.) Vernon and Martin have brought two drivers, Gordon (Noah Taylor) and Harry (Jack Reynor). Chris and Frank have brought two goons, Steve-O (Sam Riley) and Bernie (Enzo Cilenti). All four of these hired help fall somewhere on the scattergram between criminally stupid and dangerously annoyed.
Then there are Ord (Armie Hammer) and Justine (Brie Larson), the expediters who are brokering the deal from opposite sides and who believe themselves to be above the general sleaziness of everyone else. Hammer’s Ord is a very particular breed of 1974 suave, from his black turtleneck and Cambridge beard to his diction to his attitude, which is a mixture of superior and stoned. Ord believes he’s always on top of the situation, even when mayhem descends in full fury, and he’s delightfully right, even when he’s wrong — it’s a break-out performance for Hammer and the final proof for some of us that he’s more than the Winklevi from “The Social Network.”
Larson’s Justine, by contrast, knows enough of men to distrust everyone and everything while battening down for survival.
“Free Fire” shows British director Ben Wheatley (“High Rise,” “Sightseers”) at play in the fields of Quentin Tarantino. The movie’s a hermetically sealed Roach Motel: A bunch of malefactors go into a building, not many come out, and the deciding factors are luck, nerve, and ammo. Every conceivable comic variation is run on how things can go wrong, with the screenplay by Wheatley and his wife and writing partner Amy Jump regularly folding in new elements: a ringing telephone, a betrayal or three. At a certain point most of the characters have been winged by a bullet and are incapable of walking upright. The ensuing battle of prostrate criminals is this close to Beckett.
You could argue that “Free Fire” is set in Boston only for the IRA connection. There’s not much local scenery, but the air of sublime defeatism feels about right. The whole thing plays like a novella discovered in the bottom of one of George V. Higgins’s discarded law folders, or a fever dream Dennis Lehane might have after one too many boilermakers at J.J. Foley’s. It’s a sketch, but a righteously rude one.
Still, having worked through its permutations, each character coming hellaciously up against the others, “Free Fire” eventually runs out of ammunition. Worse, it doesn’t stick the landing. Wheatley has made a closed box of an entertainment, an almost perfectly constructed exercise with no larger meaning, and in the end he has no choice but to admit it.
But while the rats are running his maze, it’s something to see.
Directed by Ben Wheatley. Written by Amy Jump and Ben Wheatley. Starring Brie Larson, Cillian Murphy, Armie Hammer, Sharlto Copley. At Kendall Square. 90 minutes. R (language throughout, drug use, lavishly gratuitous gunplay).Ty Burr can be reached at firstname.lastname@example.org. Follow him on Twitter @tyburr.