Jay (Neil Maskell) is just your ordinary bloke – he forgets to buy the loo roll, he stocks up rather too generously on the old wine, he loves his wife and his young son more than anything and is all too aware that, despite his best efforts, he’s constantly disappointing them. After yet another argument with wife Shel (MyAnna Buring) about their lack of cash, Jay reluctantly agrees to go back to the employment that kept them sitting pretty for 8 months – life as a no-nonsense contract killer alongside best mate Gal (the glorious Michael Smiley). Just one job, Gal assures him, one more job and Jay will be set. Just a list of names, a wipe-clean automatic weapon, a couple of weeks and they’ll be off the hook. And after all, as Jay himself states, when examining who they’ve promised to kill – “they’re bad people. They deserve to suffer”.

From the word go Kill List doesn’t feel like your average hit-man thriller. Though the premise seems fairly standard – two mates, a list of victims, a murky past and an evidently bloody future – an eerie score throbs and tinkles in the background, as if trying to warn us of strange things to come. The shots too seem oddly impatient, cutting off dialogue mid-way through conversations, slicing through scenes of domesticity and shoving us without apology forward on Jay and Gal’s death-quest. Though at the beginning this seeming desire to Get To The Action could easily be written off as wanting to settle onto the slippery slope of blood-lust, director Ben Wheatley keeps tripping us up on snippets of scenes that are utterly baffling, leaving you wondering what on earth he’s playing it. Halfway through a dinner-party, for instance, Jay, wife Shel, Gal and his date Fiona are enjoying copious amounts of alcohol when Fiona slips away to the bathroom. Working quickly and carefully, she gently takes down the mirror, carves a mysterious symbol onto the back of it, and then replaces it, smiling softly. There’s no time to worry about it, Wheatley’s next four shots have already taken place in the time it takes for the act to register, and all that’s left is a vague unease that, as an audience member, you couldn’t be less in control.

As the pace picks up, the list in question gets shorter and Jay feels increasingly like something sinister is taking place, his already short fuse gets cut to the point of brutality. His victims suffer the consequences, facing bloodier death after bloodier death, and with only easy-going Gal to keep Jay from losing it completely the film twists madly from unrelenting gore to laugh out loud dialogue, sometimes within a matter of seconds. The chemistry between Maskell and Smiley is astonishing, and their easy back and forth adds yet another dimension to a film that’s already straddling about four genres with ease. As Jay struggles to understand his own feelings of dread the film lurches faster and faster in the direction of its climax, and when it finally lifts the lid on its secrets it utterly explodes; discarding its initial premise as a buddy-thriller and plunging into full-on horror.

Wheatley never loosens his grip for a second – every shot is perfectly calculated to shock, thrill, terrify and baffle as he desires – finally working up to a denoument that will leave you speechless. There’s no denying that the final revelations are perhaps less cunning than the achingly slick build-up would have you hoping for, but by gum do they keep you glued to the screen until the final – predictably bloody – moments. A must-see for horror fans everywhere, a masterclass in tension and a dark thrill-ride we won’t soon forget; Ben Wheatley, where on earth have you come from?