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.
as Hercule Poirot
as Dr. Graham
as Lord Amery
as Caroline
as Inspec. Japp
as Butler
as Barbara
as Lucia
as Richard
as Cap. Hastings
as Raynor
as Dr. Carelli
