Schüsse in Kabine 7.

The Minerva Mines Company is interested in transporting two particularly valuable diamonds from Cape Town to Amsterdam. To confuse potential thieves, two detectives are sent on two different ships with steel suitcases and they have no clue whether they’re carrying pebbles or diamonds. Nevertheless, a collection of questionable characters come on board both ships. The hunt for the diamonds begins; the suitcases are stolen; everyone is suspect.