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.
| Actor | Role |
|---|---|
 Carlo AldiniPierre Lafitte | Pierre Lafitte |
 Eve GrayLucienne Fereoni | Lucienne Fereoni |
 Hilda BayleyRita van den Meer | Rita van den Meer |
| EElfriede BorodinJeanette Finné - seine Schwester | Jeanette Finné - seine Schwester |
 Eberhard LeithoffGeorge Finné | George Finné |
 Shayle GardnerJulius Vardier - Staatssekretär des Innern | Julius Vardier - Staatssekretär des Innern |
 Hans MierendorffMarglin - Chef des Geheimdienstes | Marglin - Chef des Geheimdienstes |
 John MylongBoris | Boris |
 Valy ArnheimWittington | Wittington |
| MMikhail RasumnyNot listed | Not listed |