The inventor Sir Claude Amery wants to give the thief of the formula for his latest invention the chance to return it in the dark without being recognized. He gathers everyone in the house in the library and has the lights switched off for a short time. When the light comes back on, Amery is dead. A case for the Belgian master detective Hercule Poirot.
Horst Bollmann
as Hercule Poirot
Heinz Fabian
as Dr. Graham
Ernst Fritz Fürbringer
as Lord Amery
Käthe Haack
as Caroline
Gert Haucke
as Inspec. Japp
Otto Kurth
as Butler
Anita Lochner
as Barbara
Ulli Philipp
as Lucia
Jochen Schmidt
as Richard
Jochen Sostmann
as Cap. Hastings
Friedrich von Thun
as Raynor
Herbert Weicker
as Dr. Carelli
