After living all his childhood in the street, a young boy rapidly notices that crime doesn't pay, leading him to become a policeman. One day, one of his best friends goes to prison for a murder he didn't commit. The policeman tries his best to release the friend by proving his innocence.

A mad killer is on the loose in a hotel on a dark, gloomy night.

Tarzan spurns the love of La, Queen of Opar. When he isn't trying to keep the Bolshevik Rokoff and Clayton (pretender to the Greystoke estate) from reaching Opar, he is attacked simultaneously by two lions, dropped into a pit when a volcano splits the ground, nearly sacrificed by sun worshipers, and so on.

Mary Brooks' father, who has been studying ancient tribes, falls into the hands of "the people of Zar, god of the Emerald Fingers." Tarzan helps Mary locate her father, rescues everyone from the High Priest of Zar, and takes Mary to his cave.

Ken and Happy, looking for their friend Cherokee, run into an outlaw gang led by Ritter who have been terrorizing the ranchers. Ken figures that one of the prominent citizens is the real boss and sets a trap to find him.

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.

When a deadly Nitron ray strikes Earth, Flash Gordon and his friends travel to Mars to battle Ming the Merciless and his new ally Queen Azura.

A gold-digging woman wins a big settlement against an older married man, which threatens to destroy the man's family. His son, discovering that the woman is part of a ring of blackmailers and that she is planning to flee the country, takes along his hulking chauffeur and follows her onto an ocean liner. There the two pretend to be a pair of wealthy playboys so that the woman will make a play for him and try to blackmail him, too, so he can then expose her and prove his father's innocence. Complications ensue.

A madman sets out to destroy a group of Chinatown merchants.

Working as a manicurist at the Ritz, Helen Thurston, is in love with her wealthy patron, Jack Standring, but the young man's mother wants him to marry a rich debutante. Helen is informed that she has inherited her grandfather's millions, and she proceeds as quickly as possible to acquire expensive clothing and jewelry on credit. Jack, however, is not impressed. Soon Helen learns that she has inherited only $1,000, the remainder of the fortune having gone to her cousin Spindrift. The creditors hound her for their money, and at a grand ball at the Standring home, a detective threatens to arrest her. Touched by her poverty, Jack decides to elope with her. Finally Spindrift violates the conditions of the will, and Helen inherits the entire fortune.