Monica Ross

Celebrated crime writer Colin Knowles finds himself at the centre of a baffling real-life mystery when his estranged wife Louie asks for his help. Her new boss has gone missing at his grand country home -- and when his body is found, the hunt is on for a devious and twisted murderer. Sinister letters from London refer to a 'double crime'. Who will be the killer's next victim?

A rich but disliked elderly man invites his relatives to a family reunion at his home. Once the gathering is complete, he announces enigmatically that he intends to change his will before he dies. Before he can do this, he is murdered. His niece (Gynt), a detective story writer, has to put her theories into practice by solving a real-life murder mystery.

When a beautiful young artist's model is strangled in her bed, Scotland Yard find themselves with three suspects -- her sinister ex-husband (Elwyn Brook-Jones), a sexually disturbed artist (Ballard Berkeley) and her violent new boyfriend (John Bailey), who is prone to unexplained blackouts.To catch the killer, the police must set a dangerous trap with the aid of a famous sculptress (Hy Hazell).

David Anthony, a Harley Street physician, swaps duties with his brother, a medical missionary in Africa.

David and Monty are two friends of Susan and Betty Potter whose father runs a fleet of lorries. One by one, his lorries are involved in accidents and sabotage is suspected. The children are determined to find the culprits.