In 1783, Kitty (Goddard) is caught trying to pick the pocket of the painter Thomas Gainsborough (Kellaway). He offers to pay her more to sit for a portrait for him. There, she attracts the attention of Sir Hugh Marcy (Milland) and the Earl of Carstairs (Knowles). Sir Hugh, upon finding out her real social status, offers her a job as a scullery maid. Kitty learns that he is impoverished, having lost his post in the foreign office due to a scandal.