Van Duylen, representative of a diamond syndicate, brings to Amsterdam the Koh-I-Noor II , the largest diamond ever found. In one of the city's oldest diamond-cutting establishments it is cleft and the nine small stones are polished. Escorted by detectives, Van Duylen takes the stones home and puts them in his burglar-proof safe. He tells his wife that its doors are electrically charged and that anyone opening them in the wrong way will immediately be electrocuted. Two suspicious persons, Jack the Acrobat and the lion-tamer Feenstra, prowl around Van Duylen's villa, inspecting the doors and windows.
| Actor | Role |
|---|---|
 Adelqui MigliarPim Bruce | Pim Bruce |
| MMary BeekmanVrouw van de huisvriend / Wife of the family friend | Vrouw van de huisvriend / Wife of the family friend |
 Aaf BouberVrouw van Veerman | Vrouw van Veerman |
| JJan CijschHuisvriend / Family friend | Huisvriend / Family friend |
| HHenni HillebrandJack | Jack |
| HHerman HulsmanDiamanthandelaar / Diamonddealer | Diamanthandelaar / Diamonddealer |
| MManus HulsmanVan Duylen | Van Duylen |
| HHendrik KammemeijerAgent / Policeman | Agent / Policeman |
 Jan Lemaire Sr.Kantoorbediende / Clerk | Kantoorbediende / Clerk |
| HHetty RuijsVrouw van de diamanthandelaar / Wife of the diamonddealer | Vrouw van de diamanthandelaar / Wife of the diamonddealer |
| JJacques SequeiraDiamanthandelaar / Diamonddealer | Diamanthandelaar / Diamonddealer |
| JJacques van HovenKantoorbediende / Clerk | Kantoorbediende / Clerk |
| PPiet FuchsDierentemmer / Animal tamer | Dierentemmer / Animal tamer |
| DDirk JanseNelis Veerman | Nelis Veerman |