Based on Agatha Christie's "The Secret Adversary," a young couple looking for adventure become involved in the mystery of a missing woman and an espionage ring.
From Rotterdam, Gerhard Bern has received the terrible news that, for no ostensible reason, his brother has committed suicide. The only clue seems to be his membership of a secret club. To find an explanation, Gerhard, accompanied by a detective, hurries to Rotterdam, where he is given...
