At cinemas nationwide now.

Reaching audiences just in time for awards season and telling a true life tale of childhood trauma and adulthood soul searching, on paper Lion has all the ingredients of a heartstring puller. If Manchester by the Sea and Jackie tackle pain with subtlety and stylisation respectively, expectation would be for this film to stick closer to template: big emotional beats that draw tears from wells always fit to burst.

To its credit, Lion is not that film. It is, however, one of two halves.

The first is the more successful. It tells the story of young Indian boy named Saroo (Sunny Pawar), who is separated from his older brother when, tired after a night time journey, he falls asleep on a train, unable to disembark until he has travelled halfway across the country.

As Saroo alternately finds himself either alone, or surrounded by faces and words entirely alien, sequences of his desperate search and struggle to survive verge on terrifying. Utilising Pawar’s sweetness and slightness in equal measure, swift cuts and intense sound design place us in a world that is so much bigger than him, reminding us of the disorientation and vulnerability only a child can feel. Did you ever panic after losing your mum in a shop? Remember that moment. Now imagine it’s the day before Christmas and that supermarket is the size of a city – and your mum isn’t even inside.

It’s not perfectly done, with some moments feeling a little by-the-numbers (unfortunately, years of storytelling convention have taught us never to trust a nice stranger), but is definitely more compelling than the film’s second half. Here we meet an adult Saroo (Dev Patel), now happily living in Australia following his adoption by kind-hearted Tasmanian couple, Sue and John (Nicole Kidman and David Wenham). Happy, that is, until a university party triggers emotional memories of his past.

With help from ‘this new computer program, Google Earth,’ Saroo uses what little information he has to try to rediscover his home, but obsession soon begins to strain relationships with both his family and his girlfriend (Rooney Mara, given far too little to do).

It is here where things begin to get a little cyclical. The film is nearly two-thirds into its run-time when Saroo begins his search, yet with multiple scenes dedicated to him scrolling on a laptop screen, placing pins on maps and becoming slightly unkempt (none of it really conveying any sense of time), the pacing feels off-balance, as if the credits are going to roll while we’re still 20 minutes short of a conclusion.

The result is a remarkable story that feels let down by the telling; a Lion that grabs your attention with a roar, then just curls up on the sofa and slowly falls asleep.