India's railway network began under British colonial rule in the 19th century and now runs 71,000 miles of track through more than 7,500 stations, carrying millions of people every day. This film rides that system at its most extreme, following packed carriages through punishing heat and stopping at historic stations including Muzaffarpur and Lucknow. Along the route it traces the railway's tangled political history, from its role in the Sepoy Rebellion and Gandhi's campaigns against colonial rule to the mass displacement of Partition, when trains carried refugees across a newly drawn border. It also looks at present-day pressures on the system, including the introduction of women-only carriages as a response to overcrowding and harassment. The journey ends on the Kangra Valley Railway, a narrow-gauge line climbing into the Himalayas, a sharp contrast to the crush of the mainline trains earlier in the film. Interviews with passengers and railway staff sit alongside on-the-ground footage of platforms, crowds, and cabins throughout.