When his Granny comes down with a mysterious ailment, Franklin and his friends must search for the treasure of Turtle Lake. This is said to be a talisman that can cure the illness.

A pessimistic urban drama, with a musical score by Jack Sels and Max Damasse, charts in strongly expressionistically lit black-and-white images the wanderings of a tormented man through the cosmopolitan port city of Antwerp. The only people to show him understanding are an orphan and two disillusioned women.