For his vivid world-building on the Mad Max series; for the bracingly subversive spin he brought to Babe: Pig in the City; even, at a push, for Happy Feet, George Miller has earned the right to indulge himself with a colossal, extravagantly ugly folly of a movie. But just because he has paid his dues, it doesn’t necessarily mean that audiences will share the director’s enthusiasm for the tale of Alithea (Tilda Swinton), an academic who unleashes a djinn, or genie (Idris Elba, with elf ears), from a bottle and then vacillates, for what seems like a sizeable chunk of the 3,000 years in question, about whether or not to make a wish.

On paper it’s a romantic fantasy – the djinn regales Alithea with tales of his three millennia (including three separate instances of getting trapped in various vessels) – but there’s something rather sterile and bloodless in the film’s approach, with its synthetic and soul-sappingly clean-looking CGI. Plus there’s the palpable lack of chemistry between the leads: a kind of brisk civility rather than the ache of eternal longing the title promises.