When Fiona Macleod is sent by her guardian aunt and uncle to spend a London season with the Tribble sisters, it is something of a last resort. At nineteen Fiona is a beautiful and wealthy Scottish heiress. Yet for some mysterious reason, her several proposals of marriage over the past few years have all fallen through at the last moment.

Amy and Effy Tribble, professional chaperons whose School for Manners has recently made them the talk of fashionable London society, are always short of cash and gladly take on Fiona as a new client. They promise to reform the girl, train her in proper comportment and the feminine arts, and guarantee a mutually profitable marriage by the end of the season, taking Fiona off her guardians' hands forever. But when Fiona arrives at the Tribble sisters' shabbily genteel London townhouse, she shocks them by behaving perfectly. They are thoroughly puzzled by their seemingly demure new client, until they take Fiona to her first ball and realize that their charge is an incorrigible flirt.

Face-to-face with Lord Peter Havard, the season's most unattainable rake, Fiona loses her composure, betraying her real feelings—and the Tribbles are forced to confront the truth about her past. It may be too late to salvage Fiona's reputation, but the Tribbles—who have never claimed to be perfect—must also consider their own reputations.