Sam Rockwell’s in typically oddball form as an American ex-con enticed into pulling off a heist in London.

Smart but gawky English lawyer Phoebe Fox persuades Rockwell and his fellow parolee buddy (Ben Schwartz) to help her clear her debt to a big-time gangster (Peter Polycarpou).

In a highly contrived plan, Fox has to intercept a package being exchanged at the Natural History Museum – which is where Rockwell and Schwartz come in. Naturally, the stickup fails to go exactly to plan.

Some viewers will find the mix of quirky comedy and gory thrills jarring, and at times it’s a bit self-indulgent, but the performances should draw you back in.

Peter Ferdinando puts hilarious menace into the role of a violent East End crook who sports double denim and a Billy Ray Cyrus mullet, while Amanda Donohoe plays strikingly against type as his brassy Cockney mum. Simon Callow is a hoot in a brief cameo as plummy Uncle Martin, sent with a trio of equally posh chums to eavesdrop on a gang of criminals. Fox and Schwartz are great, too, but it’s Rockwell who makes the movie, zany and playful, and carrying with him both a hint of vulnerability and a whiff of danger.