A singer on a gambling ship is married to a wealthy playboy. When he is found murdered, all evidence points to her as the culprit, and she is put on trial for the crime.
Rival newspaper reporters Pat Morgan and Ted Rand find themselves unraveling the mystery behind the death of a millionaire philanthropist who fell from his penthouse balcony. When it is discovered that the plunge was not an accident, the building's residents come under suspicion. Soon, the body count begins to mount as three more murders occur by strangulation.
A man known to be a mute is suspected of committing a murder, as he was noticed at the scene. However, witnesses saw and heard him talking as he was leaving the scene of the crime. The police must determine if he is the actual killer or if he is being framed.
In London, a secret society led by lawyer Thaddeus Merrydew collects the assets of any of its deceased members and divides them among the remaining members. Society members start dropping like flies. Sherlock Holmes is approached by member James Murphy's widow, who is miffed at being left penniless by her husband. When Captain Pyke is shot, Holmes keys in on his mysterious Chinese widow as well as the shady Merrydew. Other members keep dying: Malcom Dearing first, then Mr. Baker. There is also an attempt on the life of young Eileen Forrester, who became a reluctant society member upon the death of her father. Holmes' uncanny observations and insights are put to the test.
When legendary hunter Bob Rainsford is shipwrecked on the perilous reefs surrounding a mysterious island, he finds himself the guest of the reclusive and eccentric Count Zaroff. While he is very gracious at first, Zaroff eventually forces Rainsford and two other shipwreck survivors, brother and sister Eve and Martin Towbridge, to participate in a sadistic game of cat and mouse in which they are the prey and he is the hunter.
Ruth Earlton has come home to her ancestral mansion to claim her inheritance. Accompanied by her boyfriend, she discovers that her father died suddenly under suspicious circumstances. Now it's her turn, as her deranged and relentless uncle targets her for death with the help of his wife and son, plus a very unhappy ape.
Francis, a young man, recalls in his memory the horrible experiences he and his fiancée Jane recently went through. Francis and his friend Alan visit The Cabinet of Dr. Caligari, an exhibit where the mysterious doctor shows the somnambulist Cesare, and awakens him for some moments from his death-like sleep.