In London, 1946, Miss Iris Sparks—co-proprietor of the Right Sort Marriage Bureau—has to deal with aspects of her past exploits during the recent war that have come back around to haunt her.

The Right Sort Marriage Bureau was founded in 1946 by two disparate individuals: Mrs. Gwendolyn Bainbridge, whose husband was killed in the recent World War, and Miss Iris Sparks, who worked as an intelligence agent during the recent conflict, although this is not discussed. While the agency flourishes in the post-war climate, both founders have to deal with some of the fallout that that conflict created in their personal lives.

Miss Sparks finds herself followed, then approached, by a young woman who has a very personal connection to a former paramour of Sparks. But something is amiss, and it seems that Iris's past may well cause something far more deadly than mere disruption in her personal life.

Meanwhile, Gwendolyn is struggling to regain full legal control of her life, her finances, and her son— a legal path strewn with traps and pitfalls.

Together these indomitable two are determined and capable and not just of making the perfect marriage match.