Bob Marston, a San Francisco socialite turned amateur detective is assigned to apprehend a gang of bootleggers.
A gang of crooks are employed to get possession of valuable papers of international importance, held by the French Ambassador, Vicomte de Jarlais. They are also instructed to get the Ambassador out of the way and make it appear that he has committed suicide. His mysterious disappearance arouses the United States Secret Service officers
Lois Fox, upon whose shoulder is branded a Chinese idiograph resembling the letters "A. Y.," is rescued from a gang of Chinese ruffians by Brice Ferris. His servant Ming, in attempting to steal from her finger a ring that bears a mysterious green seal, is killed, and soon afterward a stranger named Strang arrives, also in search of the girl. Despite Brice's efforts to protect her, Lois is abducted and taken to the headquarters of Lao Wing, the leader of a secret Chinese society known as the Tong.
Rosalind Joy (Helen Foster) is an heiress who has inherited a South Seas island known as Pleasure Island. A hidden cache of gold is allegedly buried on the island, which has several haunted structures. Rosalind's uncle, Spring Gilbert (Al Ferguson), wants the gold for himself and declares he will stop at nothing, not even the death of his niece, to get it. Rosalind, meanwhile, is befriended by Jerry Fitzjames (Jack Dougherty), a playwright. Unfortunately, Jerry has only recently escaped from a psychiatric hospital. Although he swears to protect Rosalind, she doubts Jerry's sanity. The two lovers race against Uncle Gilbert (who has set several traps for them) to find the treasure. In the end, Rosalind and Jerry are aided by the "Phantom Rider," a spectral horseman.
Humanitarian Roberta induces her father to hire former convict, Bill, as his gardener. When she leaves on vacation, Bill steals her jewelry and eventually sells a brooch to her boyfriend, Richard, who unknowingly gives it to her as a present.
Wade Hildreth is sent to New York from London to receive a diamond necklace for Lady Gwendolyn from the jeweler Arabin. A gang of crooks led by Pete Fielding, known as "The Shadow," plans to keep Hildreth from going to Arabin's until they have robbed the store. Actress Morn Light, whom the Shadow loves, agrees to entice Hildreth to her apartment to be imprisoned. When she warns Hildreth because she wants to avenge her father's death, which was caused by the Shadow, the Shadow overhears and captures them both.
A baby is left on the Brinbecombes' yacht while they are sailing up the Hudson River, and they adopt him and name him Everett. They are neighbors of Governor Floyd Vandecarm whose twin children, Floyd Jr. and Fledra, were kidnapped in early infancy. Their abductor was Lon Cronk, a man sent to prison by Vandecar when the latter was a district attorney of the county. The twins grow up in Cronk's shack as "Flea" and "Flukey." Despite her rough surroundings Fledra/Flea grows into lovely young womanhood and she and her brother run away from Cronk's cruelty. They reach Tarrytown and peer into the lighted windows of the home of siblings Horace and Anne Shellington. Anne brings the two young vagrants into the house and ultimately adopts them. But Cronk, aided by Everett, wages a long, evil campaign to regain possession of the children.
A man breaks into a flat, startling the occupant. They argue about the new girlfriend of the 'burglar', who's come to get her stuff. Then a third man bursts out of the cupboard...
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.
When his buddy is murdered a dedicated cop, goes after the gang responsible.
Thinking that he has lost both his money and his beloved Nora's in a bad investment young New Yorker Ted Ewing arranges for his own murder. Suddenly he discovers the money is safe and has in fact doubled and sets out to cancel the contract on his life. But will he be able to do so in time?
Most of the scenes are laid in a parrot-and-monkey country in South America, a land where "it is always after dinner." The Llano Kid, a Texas bad man, flees there from justice. The consul persuades him to play the long-lost son of a Castilian family, and tattoos a coat of arms on the back of the Kid's hand to make the deception complete. The Kid is taken into the household, trusted and loved by the gladdened mother. For the first time he has a home. The romance develops. And when the time comes to rob and flee he has too much manhood to break the loving mother's heart. The surprise comes when it is revealed that the man the Kid killed in Texas was the real son.
When her father goes broke in the stock market, Jane Lee is forced to leave her prestigious boarding school. Glad-handing John Brock, an old friend of Jane's father, arranges for the girl to be hired as his stenographer. But Brock's lecherous ulterior motives become obvious when he locks Jane in the office and tries to rape her. When she manages to escape his advances, Brock vengefully frames the girl on a robbery charge.
John Hampstead gives up his career as an actor and his actress sweetheart, Marian Dounay, to become a minister in a western town. Marian appears, and failing to win him back she tries to ruin his reputation. Hampstead is accused of stealing some jewelry though actually he is protecting the scapegrace brother of his current sweetheart, Bessie.
Two men, one of them a villainous hypnotist, contend for the same woman, unaware that she suffers from dual personality disorder.
In Africa a typist is framed for killing a diamond smuggler who betrayed her father.
Old Silas Blackburn, a wealthy recluse, lives alone with his butler and his ward Katherine. One night, Katherine discovers Silas murdered in the room where three generations of Blackburns have mysteriously died. Silas' grandson Robert, whom Katherine loves, comes to visit the next day, suffering from amnesia.
Jim Crosby, the product of a broken home, becomes a gangster and goes to prison. Meanwhile, Ann Payton, an heiress, converts a saloon into a mission. She is engaged to her father's secretary, Temple Vaughn, a gambler. Jim is released from prison and seeks shelter at the mission. Temple becomes indebted to gambler Phil Johnson and is forced to arrange a crooked poker game involving some of his wealthy friends. Jim overhears the plot and, realizing that Temple is Ann's fiancé, robs the poker game and puts a check Temple forged into Temple's own pocket.
A reporter and a detective team up to solve the murder of a nightclub singer who had been involved in a divorce scandal.
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.