Five-year-old Saroo lives in northern India. His biggest dream is to grow up and be able to do all that his older brother can. After accidentally catching a train and falling asleep, he wakes up alone and confused hundreds of miles away from home. Nobody understands what he's saying, nobody seems to want to help him and he's forced a time to live like street children in dangerous Calcutta. Saroo eventually ends up in a orphanage from which he tries to find his family without results and he is eventually adopted by an Australian family who gives him all the love and care he has long been missing. In order not to hurt the feelings of her adoptive parents, Saroo rarely mentions his past life and burys his hope of ever reuniting with his true family. When a college friend many years later suggests that he try to find his hometown with Google Earth, he thinks that it's a crazy idea. But the thought is staggering and he makes his first search using the fragmentary memories he still has.