Starting in Kolkata, Sergeant traverses India from east to west, travels through turbulent Bihar state, visits the Victorian railway town of Jamalpur, and discovers why the construction of the Dufferin Bridge at Varanasi resulted in Victorian technology and ingenuity clashing with ancient religion, before ending his journey at the border with Pakistan. Even though Mahatma Gandhi denounced the railways as evil, Sergeant reveals how it became a civil engineering triumph that united the country and played a crucial role when India became independent in 1947.

John Sergeant continues his 3,000 mile journey along India's rail tracks, travelling north to south to discover how the railways not only shaped its history but also its future. Starting in New Delhi, John reveals how the railways' extraordinary construction story began with locomotives and track being shipped from British shipyards. He visits Gwalior to discover the extent of collusion between the privileged maharajahs and the British Empire, and at Victoria Terminus he reveals the politics and the power behind its grand design. But it is at Bhore Ghat - just outside Mumbai - where John discovers the 19th century British engineers' crowning construction achievement and the extraordinary human cost that made it all possible. He concludes that today it is India's railways that continue to change the lives of its one billion people in ways that would have delighted its colonial architects.