After being fired from several governess positions, Miss Guinevere Pettigrew (Frances McDormand) stumbles into the fast-paced social life of Delysia Lafosse (Amy Adams). When the employment agency refuses to send her out for any more jobs, Pettigrew sneaks off with Lafosse's contact information, then shows up at her London flat expecting to find another rich-mother-and-spoiled-child combination to take care of.
Instead she walks into a den of sin. And as the daughter of a vicar, Guinevere finds the moral atmosphere in Delysia's apartment quite repugnant. Miss Lafosse, you see, has one man in her bed and another on his way up to see her. Pettigrew, who spent the previous night in a soup kitchen, at first attempts to dismiss the misdeeds of darling Delysia. But Guinevere is in despair: She has nothing to cling to and no home to go to. Because she needs this job, she helps Delysia cover up her sexual exploits.
Ironically, both women are hungry and on the brink of homelessness. Delysia must pick one of the three men she is sleeping with to marry. Class distinctions become central as Lafosse tries to choose among Nick or Phil (both of them wealthy and powerful) or Michael (the only one who really knows her and loves her -- and who, of course, is also a penniless pianist).
The way McDormand and Adams play off each other is magical. With Pettigrew raising an eyebrow and Lafosse smiling deviously, Miss Pettigrew is the much-overdue girl-buddy movie that many women have been waiting for. (Rated PG-13)