Eight people at a remote Scottish inn find themselves confronted by a woman from Mars, who has landed her flying saucer for repairs but intends to soon conquer the Earth and enslave its men for breeding purposes.

Several murders of nuclear scientists, that baffles Scotland Yard, occur in London around the same time that Bill Locklin, a special officer from the United States State Department, arrives to oversee the transfer of Professor Leon Dushenko, a Russian scientist who has fled the USSR. An attempt on Dushenko's life is made with a monkey's paw-print found at the scene.

A slick young man buys a jewel with a cheque that bounces. He then disappears and both the police and a lawyer try to find him. The lawyer hires a female detective to track down the missing man, but when his body is found in the Thames the case is by no means over.

An escaped murderer flees France to England, where he forces an ex-forger, now established as a reputable estate owner, and the forger's daughter who knew nothing of his past, to counterfeit 5-pound notes for mass distribution around the countryside.

A psychopathic killer murders three girls before police catch him.

A compilation of 3 stories, "The Wedding Gift", "The Thief of London" and "The Final Twist". Originally part of the Danziger Brothers series "Calling Scotland Yard"

Two reporters are held hostage in old castle, by thief, looking for jewels, that he had buried, after robbing a local house.

An American travels to East Africa, where he tries to find out how his brother died.

Because she dials the wrong number, an old lady hears information which enables the police to solve a robbery and murder.

Scotland Yard is called in when the effigy used in a Guy Fawkes Day celebration turns out to be the burned corpse of a real man.