Barborka and Tomík vacation at their grandparents at the smithy beneath Dragon Rock, where the double-headed dragon Čmoudík (Smoky) is working hard.

Police officer Jack Wild discovers that the well-known international terrorist Hans Becker is on a train, carrying a wealthy business man and his girlfriend. Without a second to loose Jack hires a helicopter to drop him down onto the train to try and stop whatever scheme Becker is planning.