Valuable documents have been stolen from a British laboratory. Slim Callaghan is sent to investigate the theft. But his tracks soon lead him to the welcoming skies of the Côte d'Azur. There, he decides to infiltrate a network of aristocratic spies.
| Actor | Role |
|---|---|
 Tony WrightSlim Callaghan | Slim Callaghan |
 Magali VendeuilDoria Varette | Doria Varette |
| RRobert PerryCount Haragos | Count Haragos |
 Jean-MaxCommodore Schoubersky | Commodore Schoubersky |
| DDiana BelIrania Trasmonti | Irania Trasmonti |
 Mario DavidAmédée | Amédée |
 Joé DavrayInspector Vadet | Inspector Vadet |
 Michel EtcheverryProf. Ephraim Ponticollo | Prof. Ephraim Ponticollo |
| MManuéla De Ségovia'La Montalban' | 'La Montalban' |
| AAgostino VascoNot listed | Not listed |
| CChristiane BarryCountess Haragos | Countess Haragos |
 Robert BurnierNicholls | Nicholls |
 Fernand RauzénaGonzalès | Gonzalès |
 Jean Clarieux(uncredited) | (uncredited) |
 François Darbon(uncredited) | (uncredited) |
 Christian Marquand(uncredited) | (uncredited) |
 Frédéric O'BradySouvaroff (uncredited) | Souvaroff (uncredited) |