Arthur Simon Simpson is a small-time crook biding his time in Greece. One of his potential victims turns out to be a gentleman thief planning to steal the emerald-encrusted dagger of the Mehmed II from Istanbul's Topkapi Museum.
| Actor | Role |
|---|---|
 Melina MercouriElizabeth Lipp | Elizabeth Lipp |
 Peter UstinovArthur Simon Simpson | Arthur Simon Simpson |
 Maximilian SchellWalter Harper | Walter Harper |
 Robert MorleyCedric Page | Cedric Page |
 Jess HahnHans | Hans |
 Gilles SégalGiulio | Giulio |
 Akim TamiroffGerven the Cook | Gerven the Cook |
 Titos VandisHarback | Harback |
| EEge ErnartMajor Ali Tufan | Major Ali Tufan |
 Senih OrkanFirst Shadow | First Shadow |
 Danyal TopatanSecond Shadow | Second Shadow |
 Joe DassinJoseph | Joseph |
 Despo DiamantidouVoula | Voula |
 Faik CoşkunTavla Player at Hilton (uncredited) | Tavla Player at Hilton (uncredited) |
| AAmy DalbyNanny (uncredited) | Nanny (uncredited) |
 Jules DassinTurkish Cop (uncredited) | Turkish Cop (uncredited) |
 Selahattin IçselTavla Player at Hilton (uncredited) | Tavla Player at Hilton (uncredited) |
 Bedri ÇavusogluPolice Officer (uncredited) | Police Officer (uncredited) |