Majid Majidi is the Iranian director who established himself most satisfyingly with the 1997 gem Children of Heaven, a very charming and sweet-natured tale about two children, a brother and sister. His latest movie is a departure: a slightly misfiring Hindi-language Bollywood-style melodrama set in the Mumbai underworld, with a forthright musical soundtrack from veteran composer AR Rahman. It, too, is about a brother and sister, but they are older and more disillusioned.

Amir (Ishaan Khattar) is a kid working for a sinister gang boss and sex-trafficker, couriering drugs around town on his motorbike under cover of making fast-food deliveries. On one occasion he is chased by cops and desperately implores his sister Tara (Malavika Mohanan) to hide him and the wrap of coke he has on him. Akshi (played by the actor and director Goutam Ghose), an acquaintance of Tara’s at the market where she works, bundles Amir into a pile of his clothes as the cops come through. Later, Akshi makes violent sexual demands on Tara in return for having helped, and she hits out at him. Soon Akshi is in hospital and Tara is in prison awaiting trial for attempted murder. If Akshi dies things will go badly for her.

The parallel lives of brother and sister thus play out on the ironically wrong tracks, with the career petty criminal outside jail, and innocent Tara befriending a small child in prison. Then Amir somehow becomes involved with Akshi’s extended family, having posed as his friend to gain access to his bedside to make threats. The film ends on an interestingly unstressed note, with untied plot threads and an emphasis on the imagery of the title. But until then, it is brash Bollywood stuff, and I’m not certain the very dark and grimly realistic elements are entirely absorbed into the unrealistic sentimental style of the film.