Five year old Saroo gets lost on a train which takes him thousands of kilometers across India, away from home and family. Suddenly the boy finds himself alone in the buzzing city of Calcutta. Years later, Saroo is living a privileged life. His path took him from the streets of Calcutta to an orphanage where he was adopted by the loving and prosperous couple Sue and John Brierley, who took him back to Australia. For twenty years Saroo tried to forget his past, but the urge to pick up the story of his childhood in India remains stronger. However, how does one find the proverbial needle in a haystack? Using his faded memories and the benefits of the Internet, Saroo sets of on an adventurous journey into his own past.