After the age of steam, Flying Scotsman found a new life as a heritage attraction, touring the globe. Businessman Alan Pegler saved Scotsman from the scrapheap, and took it on an ambitious 1969 tour of America before mounting debts bankrupted him, and there wasn't enough money to bring Scotsman back to Britain. But today, more than a century after it was built, painstaking restoration means the engine is still steaming across the UK.

Flying Scotsman is the world's most famous steam locomotive. Built in 1923, it became a symbol of the golden age of steam and an enduring example of British design and engineering. The first episode reveals the secrets of Flying Scotsman's groundbreaking design by legendary engineer Sir Nigel Gresley - including a corridor between the cab and the coal tender that allowed a change of crew without stopping.