The Limbo Line (novel)
The Limbo Line is a 1963 spy thriller novel by the British writer Victor Canning. A former British secret service agent Richard Manston is called out of retirement to tackle a Soviet spy network kidnapping recent defectors to be taken back to Moscow.
The book acts as a prequel to the four Rex Carver novels in that it introduces the Government agency that Carver is later unwillingly drawn into. Manston also appears as a character in some of the Rex Carver books.