Suspense "The Man Who Knew How" August 10, 1944

An interesting story about a man who knows the name of a secret chemical that can kill without a trace. + Charles Laughton as Mr Pender law abiding citizen of suburban London who meets a man on the night train and gets in to a conversation on fictional murderers in books and real life murderers. Pender tells the man that he knows how to commit a murder in an undetectable way by using a potent formula which alone would not kill but would be fatal if the person was to take a hot bath a few hours or even days after taking the potion. It is remarkable how many people have been found dead in their bath of late.