Frankenstein's unscrupulous colleague, Dr. Bohmer, plans to transplant Ygor's brain so he can rule the world using the monster's body, but the plan goes sour when he turns malevolent and goes on a rampage.

Chan is faced with suspects in a stolen atomic bomb formula case, that are being killed with bullets that are not fired from a gun.

A man listens to his wife and fakes his own death so that she can get her hands on his insurance policy.

In San Francisco, detective partners Jack Packard and Doc Long are hired by socialite Jefferson Monk who believes someone is following him with the aim to kill him.

A San Francisco airplane bound for South America crashes, and among the scorched debris is found a shrunken native human head, neatly packaged. The perplexed police contact a local anthropology museum about this unclaimed piece of grisly baggage, where they intersect with Jack and Doc, two private eyes, called there to meet a mysterious woman who had a case for them and wanted to meet in private.

"The Unknown" was the final entry in Columbia’s I Love A Mystery series. A woman hires two detectives to keep her alive long enough to claim her inheritance.

Dr. Christian takes time out from his appointed rounds to help clear a bank teller of embezzlement charges.

Career-slipping movie star Carole Raymond buys in as a real estate partner of Jeff Caldwell. Actually, through his secretary, Nola Reed, Caldwell runs a matrimonial bureau and, with the aid of his associate, Lee Kirby, they defraud and blackmail a large group of lonely people. Carole, unknowingly, is used as bait for one of their victims, Walter Desmond, who "commits suicide." Reporter William Tyler thinks otherwise.

Rawley University is about to receive a star athlete who could give it the first championship rowing team it's ever had. Unfortunately, he gets drafted into the army before he's able to join the team. Two of the team's members get the bright idea of passing off a burly truck driver as the "athlete". Complications ensue.

This tale of two tugboats focuses upon the rivalries between two operators competing to win a major shipping contract. Meanwhile a tugboat office secretary and an ex-con who wants to go straight, fall in love. Tugboat Annie is put in charge of a child violinist. When a waterfront fire breaks out, the two warring captains join forces to put it out.