Railway employee Fritz Marr is not regarded well by his superiors. It is the year 1920, and trains regularly pass the railway hub of Erfurt to the East to secretly transport weapons for the fight against the young Soviet Union. Marr knows about this and wants to mobilise other workers to stop these illegal deliveries. To muzzle him, Marr is relocated to a remote rail work construction site.

Several children find out what's the matter with a wreck offshore, which puts them into jeopardy.