An escort composed of three people transports a huge amount of new one-hundred crown banknotes in a special railway car. At the 196th kilometer, a village girl is waiting at the railway crossing and spots two men removing some packages from the track. The scene is immediately followed by the report of a gun and the unwanted witness is shot dead. Soon afterwards, on the 201st kilometer, the train explodes. Only one of the escorts Lenk (Radoslav Brzobohatý) survives the explosion, taken to hospital with serious injuries. Criminologist Major Kalas (Jirí Sovák) and the very young Second Lieutenant Karlícek (Jaromír Hanzlík) patiently gather facts, leads and testimonies.