It takes a strong woman -- and an even stronger actress -- to wear a dowdy, brown governess dress, sensible shoes and unflattering hairstyle while standing next to Amy Adams, who dresses as if she were pink champagne come to life. All bubbles and sparkle and satin robe with feathery trim.

But that's how we meet the leading ladies of "Miss Pettigrew Lives for a Day," a comedy set in 1939 London and starring Frances McDormand in the title role. She's known as the "governess of last resort" at an employment agency, and she has just lost another job.

In fact, she has lost everything, from her single suitcase of clothing to her meal from the soup line that clatters to the ground. Pretending she has been sent by the employment agency, Guinevere Pettigrew arrives at the door of an American singer-actress named Delysia Lafosse (Adams), who doesn't need a governess but a social secretary.

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'Miss Pettigrew Lives for a Day'

2 1/2 stars = Average
Ratings explained

• Starring: Frances McDormand, Amy Adams.
• Rating: PG-13 for some partial nudity and innuendo.

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Or a traffic cop, as Miss Pettigrew must extract one young man from Delysia's bed while another -- a nightclub owner -- is on his way to the flat. Turns out there's a third gentleman in the wings, too.

Miss Pettigrew earns Delysia's gratitude for how she bounces her beaux, and the young redhead offers to take her shopping. "I, for one, am not running around town with Oliver Twist's mother," she says, setting the stage for the social secretary's makeover.

She trades her frightful frock for a lovely navy dress and high heels, plus a flattering, updated hairstyle. In the course of a day, she will get another chance at love and steer Delysia in the right direction, gently advising, "Trust your heart; life is short."

"Miss Pettigrew" is based on a 1938 novel by Winifred Watson that was almost turned into a movie starring Billie Burke, who famously played Glinda the Good Witch in "The Wizard of Oz."

Arriving on screen 70 years after its publication, the movie is both slightly moldy and surprisingly modern.

Adams, fresh from "Enchanted" and "Charlie Wilson's War," talks in a fast patter like a character from a 1930s comedy -- she even says "Jeepers! -- but juggles three men like a "Sex and the City" guest star. She radiates a brand of screwball confidence and, as in the Disney charmer, gets to sing, too.

Britain is on the brink of World War II, and those old enough to have lived through the Great War know the heartbreak that lurks ahead. As one says, "I don't think I can bear it again."

Directed by Bharat Nalluri (HBO's "Tsunami: The Aftermath"), the film shines in such quiet moments, the ones fueled not by frippery and champagne but by the exchange of confidences.

The story had sprung from the imagination of Watson, who died in 2002 and once told an interviewer, "I haven't the faintest idea what governesses really do. I've never been to a nightclub, and I certainly didn't know anyone who took cocaine."

Screenwriters David Magee and Simon Beaufoy ditched the drug angle but kept the 24-hour transformations.

McDormand beautifully plays Miss Pettigrew, the daughter of a clergyman who never swore in her life -- not even in her mind, she says -- and suddenly finds herself in a whirlwind of cocktails, nightclubs, romantic roundelays, art deco apartments and second chances.

In addition to McDormand and Adams, the cast includes Lee Pace, Ciaran Hinds, Shirley Henderson and Mark Strong and film newcomer Tom Payne. You can guess exactly where this story is headed, which proves to be both its charm and its comedown.