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.
In 19th century Paris, a maniac abducts young women and injects them with ape blood in an attempt to prove ape-human kinship but constantly meets failure as the abducted women die.
Sir George hires Hillary Gatt to find out more about Eric who wants to marry Lois. Gatt is murdered and the couple, married, run off to India. Old friend John Beetham sympathizes with the bride who sees that her hubby is a liar and drunk.
Mrs. Ramsey sent Jean Oliver to prison on a false charge. To get even, Jean (disguised as Madame Mystera) plans to kidnap her daughter and turn her into a thief. Love entanglements with a gangster known as "The Fox" and newspaperman Grant complicate her plans.
A beautiful showgirl, name "the Canary" is a scheming nightclub singer. Blackmailing is her game and with that she ends up dead. But who killed "the Canary". All the suspects knew and were used by her and everyone had a motive to see her dead. The only witness to the crime has also been 'rubbed out'. Only one man, the keen, fascinating, debonair detective Philo Vance, would be able to figure out who is the killer.
London. A mysterious serial killer brutally murders young blond women by stalking them in the night fog. One foggy, sinister night, a young man who claims his name is Jonathan Drew arrives at the guest house run by the Bunting family and rents a room.