It was just a small river flowing over a dam, but to five-year-old Saroo Munshi Khan it felt like a waterfall. He played barefoot under the downpour as trains passed nearby. When night fell, he would walk a couple miles home.

Home was a tiny mud-brick house with a tin roof. He lived there with his mother, Kamala, who worked long hours carrying bricks and cement, two older brothers, Guddu and Kullu, and a younger sister, Shekila. His father, Munshi, had abandoned the family two years earlier. Guddu, then aged nine, had assumed his role as the man of the house. Guddu spent his days searching passenger trains for fallen coins. Sometimes he didn’t return for days. On one occasion, he was arrested for loitering at the train station.

One day, Guddu took Saroo on a road he’d never seen before, to a factory where Guddu had heard that they might be able to steal eggs. As the boys made their way out of the coop—holding their shirts like hammocks, full of eggs—two security guards came after them, and they were separated.

Saroo was illiterate. He couldn’t count to 10. He didn’t know the name of the town he lived in or his family’s surname. But he had a keen sense of direction and paid attention to his surroundings. He retraced the journey in his mind, and his feet followed—through the dusty streets, turning past the cows and the cars, a right here near the fountain, a left there by the dam—until he stood panting at his doorstep. He was out of breath and nearly out of eggs, so many had cracked and oozed through his shirt. But he was home.

The Separation

Saroo began venturing farther away from home, confident that he could always retrace his steps. He’d fly kites with the neighborhood kids, fetch kindling from the woods, or go to the market to watch for scraps as the butchers cut up goat meat. One afternoon, he fell and split his forehead on a rock after being chased by one of the town’s many feral dogs; another day, he cut his leg deeply while climbing over a fence near a fountain.

Early one evening, Guddu agreed to take his little brother to the railway station to search the compartments for change. Saroo rode for 30 minutes on the back of his brother’s rickety bicycle. The two got on a train to Burhanpur, about two hours away, and began scouring the floorboards for money as the train pulled away. The conductor never bothered them. Though he only found peanut shells, Saroo was happy just to be with his favorite brother.

By the time they hopped off the train at Burhanpur, Saroo felt exhausted and told his brother he needed to nap before they caught the next train back. Guddu took his hand and led him to a bench. “I’m just going to go off and do something,” Guddu told him. “Stay here. Don’t go anywhere.” But when Saroo woke up later that night, his brother was gone. Groggy and dazed, he wandered onto a waiting passenger train, assuming that Guddu must have been waiting for him inside. There were only a few people in the carriage, but Saroo figured his brother would find him soon enough, so he settled back to sleep.

When he woke, sunlight was streaming through the windows and the train was moving quickly through the countryside. Saroo had no idea how long he had been asleep and jumped up from his seat. There was no one else in the carriage, and, outside, the blurred grasslands were unrecognizable. “Bhaiya!” Saroo screamed, the Hindi word for brother. “Guddu!” But there was no response. Unable to move to another carriage while the train was in motion, Saroo ran back and forth through the car, calling for his brother, to no avail. He had no food, no money, and no idea how far he had gone or was going. “It was a lot like being in a prison, a captive,” he recalled, “and I was just crying and crying.”