In 1993, a series of violent armed robberies occurred on the K3/4 international train connecting Beijing and Moscow, the only land communication line between China and Europe back then. The Chinese police engaged in a cross-border investigation and vowed to bring the perpetrators to justice. Disguised as businessmen and undaunted by danger, a special operations team led by the Railway Police set off for this investigation in the unfamiliar territory of Moscow, with only one goal in mind: to arrest the criminals and successfully extradite them back to China. The film is based on a real historical event.