At one point in Free Fire, one of the characters says “I don’t know who’s on what side anymore”. Truth be told, neither does the audience, such is the carnage of Ben Wheatley’s new action comedy.

Taking place in an abandoned warehouse after an arms deal goes wrong, we witness 90 minutes of gunfire, one-liners and some more gunfire. Featuring an ensemble cast, we have Stevo (Sam Riley), Chris (Cillian Murphy) and Frank (Michael Smiley) pitted against Vern (Sharlto Copley), Ord (Armie Hammer) and Harry (Jack Reynor), with Justine (Brie Larson) and a few minor characters lodged somewhere between it all.

Whilst sounding remarkably simple, the film is intricately designed; characters are dotted around the warehouse, taunting each other constantly. With a chamber piece like this, the emphasis is on the screenplay to keep things refreshing, with Wheatley and screenwriting partner Amy Jump spreading a bunch of quotable lines across the ensemble.

Copley and Riley stand out, the former being a whirlwind of instability and arrogance, caring more about the condition of his suit than the safety of his men, whilst the latter shines as a junkie whose initial antics cause the shootout. When seeing a gas canister go flying around the warehouse, he gleefully notes “that was awesome”; echoing our own thoughts.

The frenetic editing reminds you of some Scorsese’s finest works (he’s an executive producer here), with Wheatley and Jump remarkably managing to keep everything coherent. The prominence of music is also a Scorsese trademark, and there’s a delicious slice of juxtaposition with the use of John Denver’s ‘Annie’s Song’, being played as entrance music for the weapons and recurring throughout the gunfight.

The action does grow a tad tiresome in places, and despite a predictable finale, the film leaves you with a spring in your step. Not since Mad Max: Fury Road has there been such a pure rush of energy and visceral action, but this has another string in its bow with a script packed full of one liners.

Wheatley is rapidly building himself a distinctive oeuvre, from the psychological horror of Kill List to the black comedy of Sightseers, and now with this latest success, he should be exposed to a more mainstream audience. As Stevo uses a certain illegal substance to clear a headache, he compares it to using a “sledgehammer to crack a nut open” and this adequately describes the film; an entertaining assault on the senses, made with impeccable craft and great gusto.