When Germany invades Holland in 1940, a British intelligence officer and two Dutch diamond merchants go to Amsterdam to persuade the Dutch diamond merchants to evacuate their diamond supplies to England.
| Actor | Role |
|---|---|
 Peter FinchJan Smit | Jan Smit |
 Eva BartokAnna | Anna |
 Tony BrittonMajor Dillon | Major Dillon |
 Alexander KnoxWalter Keyser | Walter Keyser |
 Malcolm KeenJohan Smit | Johan Smit |
 Christopher RhodesAlex | Alex |
 Alfred BurkeDealer | Dealer |
 Melvyn HayesWillem | Willem |
 John HorsleyCommander Bowerman | Commander Bowerman |
 Tim TurnerDutch Lieutenant | Dutch Lieutenant |
 John Le MesurierColonel Janssen | Colonel Janssen |
| PPetra DaviesMenschi | Menschi |
 Peter SwanwickPeter | Peter |
 Carl JaffeDiamond Merchant | Diamond Merchant |
 Karl StepanekDiamond Merchant | Diamond Merchant |
 Oscar QuitakDiamond Merchant | Diamond Merchant |
| KKeith PyottDiamond Merchant | Diamond Merchant |
 George PravdaPortmaster | Portmaster |
 Frederick SchillerTugmaster | Tugmaster |
 John BaileyPort Police Officer | Port Police Officer |
 Steve PlytasBar Owner | Bar Owner |