Ellery and Inspector Queen are approached by Abel Bendigo, a member of the powerful Bendigo munitions company family, when the life of brother King is threatened. Ellery refuses the case until he learns that the government protects him.
Fearful that his father is going to be killed, a neurotic young sculptor, Howard Van Horn, calls in EIlery for help. Van Horn fears he has committed terrible crimes during his amnesia spells.
The story deals with the mysterious death of a well-known writer which takes place while a girl believed to be the daughter of her fiance is in the next room. Karen Leith is found dead by the girl, Eva, who is then accused of murder.
An insurance company is forced to pay out $50,000 on a policy when a man's wife dies in a canoe accident. The company suspects the man has killed several wives for their insurance and sends Jack Graham to bait a trap for the killer.
The mayor of New York City calls on Ellery to help solve a series of murders for which the police can find no motive but which they believe to be the work of one killer called The Cat who strangles his victims with a silk cord.
Ellery is invited to spend a weekend at the home of U. S. Senator Leander Rhodes by the latter's daughter Ellen, a capricious cutie. But shortly after Ellery's arrival, Rhodes is murdered.
Responding to an SOS from an old reporter friend, Ellery journeys to a small, unfriendly town. Upon requesting the whereabouts of his friend, he is beaten and tossed in jail. A nursery rhyme holds the solution to five accidental deaths.
Ellery is forced by a notorious smuggler, James Garvin, to accept a gift of a typewriter. Garvin is murdered and the suspects are: His daughter, his current girlfriend, his former wife, and an English diamond merchant.
Pretty young Jennifer Phillips asks Ellery to save her father from electrocution for a crime she says he didn't commit and sets off a race against time to save him.
Ellery Queen (George Nader) discovers that a statue he has recently received is eagerly sought after by a secret agent and the daughter of a deposed Middle East dictator.
Ellery helps the police investigate the death of an eccentric recluse, Janus Parr, found in his old, dilapidated house amongst a vast collection of useless items.