Claudius Bombarnac, a reporter is assigned by the Twentieth Century to cover the travels of the Grand Transasiatic Railway which runs between Uzun Ada, Turkestan and Peking, China. Accompanying him on this journey is an interesting collection of characters, including one who is trying to beat the round the world record and another who is a stowaway. Claudius hopes one of them will become the hero of his piece, so his story won't be just a boring travelogue. He is not disappointed when a special car guarded by troops is added to the train, said to be carrying the remains of a great Mandarin. The great Mandarin actually turns out to be a large consignment being returned to China from Persia. Unfortunately the train must travel through a large part of China that is controlled by unscrupulous robber-chiefs. Before the journey is over, Claudius finds his hero.