At a party thrown at the Metcalf estate, the Marquise D'Irancy's Sultana diamond disappears when the lights go out during a power failure. Suspected of the crime is William Kirkland, the wastrel son of the wealthy Kirkland family, but William's sister Diana comes to his defense. Aiding her in the investigation is Clamp, a wandering peddler.
Wealthy spinster, Rachel Innes rents a country house with her niece and nephew for the summer, only for a series of strange occurrences and a murder at the house's circular staircase to lead to shocking revelations about the home's owner and the family secrets within the house.
During a game of hide and seek, a new bride hides in a chest and remains undiscovered until a strange visitation thirty years later.
When Harlan Carr inherited his Uncle Ebenezer's "Jack-O Lantern" house and too his bride there to live, he found himself the unwilling host of a score of hungry relatives within a week. Soon, strange things began to happen. A black cat made the house his headquarters, unexplained sounds could be heard and a shadowy figure floated through the halls at night.
Guido, an artist, is obsessed with the desire for the death of Clavering, a rich man who has entered into a forced marriage with Margaret, the girl whom Guido loves. The thought accompanies him in his work, his sleep and fills his every moment. One night, he awakens from a dream in which he has murdered Clavering. The next morning, Clavering is found murdered and Guido labors under the uncanny feeling that he is the murderer. Hoping to relieve Guido's fears, Margaret induces him to paint the picture of his dream. Clavering's butler sees the painting of his dead master, and is so horror stricken that he confesses to murdering Clavering for his money.
A man and two women, suspected of stealing bonds, are traced to a country hotel. While Judith, one of the women, is out horseback riding, the other two, Walter and Vera, are arrested. When, during a storm, Judith is injured in a fall from her horse, Boone Pendleton comes to her rescue. Soon the river becomes impassable, and they are trapped in Boone's cabin, where the two fall in love.
Millionaire Joshua Barker insists that his daughter, Faith, must marry Phil Langhorne, a man that neither likes, and Faith is in love with and eager to marry her childhood sweetheart, John Temple.
Young London realtor Leonard Tavernake becomes involved with two sisters, one good and one evil, which leads to much melodrama but things work out in the end.
A woman's cheating husband is murdered at their country estate, and suspicion immediately falls on her.
While touring India, noted English criminologist Richard Duvall saves the life of a Buddhist priest who rewards him with the presentation of a wonderful crystal globe. By gazing in it the priest demonstrates that Duvall can fall into a cataleptic state and his astral body is released and is free to roam at will. Shortly afterward he uses the orbs powers to help his lady love Grace Ellicott solve the murder of her aunt and restore her fortune.
A young American man arrives in London to claim an estate he has inherited. One of the conditions is that he signs a paper stating he will never sell the estate. When he arrives at the estate he now owns, he runs into a ring of American gangsters there and discovers that the estate is the site of some buried pirate treasure.
A film projectionist longs to be a detective, and puts his meager skills to work when he is framed by a rival for stealing his girlfriend's father's pocketwatch.
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.
A world-famous pianist loses both hands in an accident. When new hands are grafted on, he is horrified to learn they once belonged to a murderer.
Two men, one of them a villainous hypnotist, contend for the same woman, unaware that she suffers from dual personality disorder.
A masked criminal who dresses like a giant bat terrorizes the guests at an old house rented by a mystery writer.
After returning home to his long-estranged mother upon a request from her deathbed, a man raised by his parents in an orphanage has to confront the childhood memories that have long haunted him.
A general store clerk and aspiring detective investigates a mysterious disappearance that took place quite close to an empty insane asylum.
A magician seeks vengeance upon the man who paralyzed him and the illegitimate daughter he sired with the magician's wife.
Chaney plays two roles: mad scientist Arthur Lamb and Lamb's "experiment", known only as the Ape Man. This hideous creature was the result of Lamb's attempts to transplant animal glands into human beings. A lost film.