Elstree Independent Films Ltd.

David and Monty are two friends of Susan and Betty Potter whose father runs a fleet of lorries. One by one, his lorries are involved in accidents and sabotage is suspected. The children are determined to find the culprits.

A trio of young boys become involved in a criminal plot.

Murderous smugglers kidnap a troublesome Bargemans son in this British crime drama, filmed on the Thames.