It is revealed the Krogers actually are Morris and Lona Cohen, who during the 1950s and 1960s worked with fellow spy Gordon Lonsdale (real name Konon Molody) photographing and encoding as microdots various pieces of material which they then sent to their colleagues in Russia, as part of a Soviet espionage network known as the Portland spy ring, which had penetrated Britain's Royal Navy.
The original West End production, starring Judi Dench and her husband, Michael Williams, as the Jacksons, opened on 26 October 1983 at the Lyric Theatre, where it ran for nearly a year.
[5] The cast included Rosemary Harris, George N. Martin, and Tracy Pollan as the Jacksons, Dana Ivey and Colin Fox as the Cohens, and Patrick McGoohan as Stewart.
[6] In 1987, Whitemore wrote a draft of an adaptation of his play for an American television production on Hallmark Hall of Fame on CBS.
Directed by Anthony Page, the acclaimed film starred Ellen Burstyn, Alan Bates, Teri Garr, and Daniel Benzali.