Frances McDormand, left, and Amy Adams in "Miss Pettigrew."

After a slow and tiresome start, "Miss Pettigrew" forges ahead with true British fortitude and class, an endearing bond forming between Frances McDormand and Amy Adams, who are ably backed by a top-notch supporting cast led by Ciarán Hinds and Shirley Henderson.

The elegant production compensates for a predictable dual-Cinderella story as a self-righteous ascetic and social-climbing bimbo teach each other how life might be more satisfying lived somewhere in between their respective extremes.

Adapted by director Bharat Nalluri (TV's "Tsunami: The Aftermath") from Winifred Watson's novel, the film follows the monumental makeover that unfolds during one day in the life of McDormand's Guinevere Pettigrew in 1930s London.

Destitute after losing the latest in a string of governess gigs and unable to find a new job because of her judgmental temperament, the impossibly high-minded Miss Pettigrew takes an uncharacteristic step: She bluffs her way into a job as social secretary to flighty American actress-singer Delysia Lafosse (Adams).

With a chaotic life that's the reverse image of Miss Pettigrew's, Delysia juggles affairs with three men: a menacing nightclub owner (Mark Strong), a boyish stage producer (Tom Payne) and a penniless pianist (Lee Pace) who adores Delysia for who she is.

The movie's first act is an awkward, unconvincing series of miscues, chance encounters and mistaken identities.

Miss Pettigrew initially is an unsympathetic stiff, while Delysia starts off as an extremely annoying variation of Adams' helpless princess from "Enchanted." It's mighty hard to warm up to either through the first third of the film.

With the introductions over, the movie begins to jell, and the characters blossom into richer, likable people. "Miss Pettigrew Lives for a Day" eventually musters enough life-force to justify its charmed little existence.

By David Germain