Dev Patel stars as Saroo Brierly, an orphan who searches for his family in India, in “Lion.” (The Weinstein Company)

“Lion” is based on one of those stories that’s almost too incredible to be true. As a young boy growing up in a poor village in India during the 1980s, Saroo Brierley got lost nearly 1,000 miles from home with no way to retrace his steps. Eventually adopted by an Australian couple, he became obsessed decades later with tracking down his birth family using Google Earth.

Brierley’s book about his quest, “A Long Way Home,” is ideally suited for the screen — with or without the seamless product placement.

Luke Davies adapted the memoir for the screen, separating the story into two distinct halves. The movie is necessarily more harrowing during its first chapter with the remarkable Sunny Pawar playing a 5-year-old Saroo. Things go awry one night after the little boy ventures out to help his brother make some money but ends up on an out-of-service train that chugs its way to Kolkata. Pawar is only 8, but he’s a spirited, adorable young actor capable of transmitting the depths of despair when it becomes clear he may never see his family again, since he doesn’t even know the name of his village.


Nicole Kidman stars as Sue, Saroo’s mother, in “Lion.” (The Weinstein Company)

Dev Patel picks up the baton to play the older Saroo. By that point, he’s a tortured soul who woos a girlfriend (Rooney Mara) only to neglect her by spending all of his time on his computer searching for a tiny spot on a map. This may be Patel’s best performance, and he was nominated for a Golden Globe for the role of a man who isn’t entirely sure who he is. During a conversation with new acquaintances, he explains that he’s from Kolkata. “What part?” an Indian man asks him. “I’m adopted — I’m not really Indian,” he explains, although he doesn’t seem entirely convinced. Soon after that, he begins having flashbacks to long-forgotten memories that he hopes might help him find his way back home.

Nicole Kidman also was nominated for a Golden Globe for playing Saroo’s mother, Sue. It’s well-deserved: She’s stunning and shattering as a slightly overprotective matriarch whose patience and compassion know no limits. She has her hands full with Saroo’s brother, Mantosh (Divian Ladwa), who has psychological wounds from childhood that may never heal. But her frustration never outweighs her tenderness.

Where the first half of the movie is a nail-biter, as Saroo teeters on the edge of danger, barely escaping multiple adults with nefarious intentions, the second has a harder time keeping its momentum. Internal journeys are more difficult to capture, and director Garth Davis struggles to make Saroo’s obsessive computer search as thrilling as his attempts to survive on the streets of Kolkata. If the pacing feels off, the film’s remarkable conclusion more than makes up for it.

Technically, the movie is a marvel with gorgeous cinematography by Greig Fraser (“Zero Dark Thirty,” “Foxcatcher”) and an aching score by Dustin O’Halloran and Haushka, who are also up for a Golden Globe.

“Lion” is a complex movie, with its profound themes of home and identity, and its tonally disparate halves. A smartly understated approach to Brierley’s story holds it all together. Sometimes the truth alone is enough.

PG-13. Opens Sunday at area theaters. Contains some sensuality. In English, Hindi and Bengali with subtitles. 118 minutes.