Downey Jr. is more than up to the challenge too. Early scenes in Sherlock Holmes are more Fight Club than sleuth-influenced, with the hand of director Guy Ritchie behind the camera being very clear. But the film soon settles down and starts to have some fun, with the able assistance of Mark Strong and Rachel McAdams, among the supporting cast.

Yet this is Downey Jr.’s show, and he doesn’t waste the opportunity. He’s an engaging leading man at the worst of times, and he’s clearly having a ball here. What’s more, it’s immensely satisfying when his Sherlock Holmes gets down to the business of solving crimes, even though there are some really quite impressive action sequences to work through first.

There are problems, of course. There’s not enough flesh on the bones of some of the characters, and the early part of the film feels very different from the latter stages. But there’s solid groundwork here for the inevitable franchise, and watching Downey Jr. reprise the role of Sherlock Holmes over the next few years should be really quite good fun too. --Jon Foster

It’s a perfectly pitched, at times rightly uncomfortable comedy, that brings together a quartet of inept terrorists, who when we meet them, can’t even put a video together without it falling into farce. It’s an opening scene that sets up Four Lions perfectly. And led by the terrific Riz Ahmed and the scene-stealing Nigel Lindsay, the company of actors rise to the challenge that Chris Morris sets them.

Four Lions isn’t a perfect film, though. The tone is a little uneven at times, and it’s very much one that’s going to feel more at home on a television than a cinema screen. But it’s still a daring, risky and at times extremely funny piece of work. And it’s one not afraid to pull the rug on you, either, never shielding itself away from the undercurrents of its subject matter. It’s the most ambitious comedy in a long, long time, and it’s credit to all concerned that it works as well as it does. --Simon Brew