Always on the Move

In the late 1970s, aboard a steam train from Ningyang to Haicheng, young railway police officer Wang Xin patrols among the bustling passengers, diligently carrying out his duties. Mistaking veteran railway cop Ma Kui for a fugitive, they begin an unlikely mentor-apprentice relationship. From initial disdain to mutual respect, Wang Xin and Ma Kui fight side by side on the frontline of railway public security. They tackle pickpocketing, human trafficking, drug smuggling, line patrolling, and theft, always prioritizing the safety of every passenger. Wang Xin and Ma Kui, representing old and new generations of railway police, witness the evolution of China's railways from steam to electric locomotives and finally high-speed trains, as they guard the safety of the nation's ever-changing railway network.