The blurb for this made it sound like a standard gangster comedy affair but it has a sci-fi twist that becomes apparent as loan shark Nick (Vince Vaughan) calls Mike (James Marsden) away from an adulterous rendezvous with his wife, Alice (Eiza Gonzalez). Mike is understandable worried he is about to get whacked for the affair but is confused when he is told to chloroform... Nick. But a different, identical Nick who is in Nick's house.
It turns out Nick 1 is from the future (it makes more sense if you have seen the brief prologue) and wracked with guilt at the death of Mike, who he framed as a rat to extract revenge for the aforementioned affair with Alice.
Things get more complicated from there, with the addition of a cannibal hitman, double and triple crosses and a some further temporal shenanigans.
This is not quite the snappy, screwball comedy it thinks it is, with some attempts at Tarantino-esque pop culture dialogue feeling a little forced, but the three have decent chemistry and the secondary characters, including mob boss Keith David, Stephen Root in a role I won't spoil and Arturo Castro as the aptly-named Dumbass Tony are enough to carry the piece.