Love's Labour's Lost is one of Shakespeare's lesser known plays, but it follows a formula that those with even casual familiarity with his comedies will recognize: Multiple couples fall head over heels in love, though fate or happenstance conspire to keep them apart, at least for a while. Identities will be mistaken, by deliberate design. Woo will be pitched, troth will be pledged, and everyone will end up happy in the end. Branagh transports Shakespeare's Kingdom of Navarre to Western Europe just before World War II but otherwise keeps the basic situation intact. The handsome young King of Navarre (Alessandro Nivola: Best Laid Plans) and his three friends -- Berowne (Kenneth Branagh: The Road to El Dorado, Wild Wild West), Longaville (Matthew Lillard: Wing Commander, Scream), and Dumaine (Adrian Lester: Primary Colors) -- make a pledge to retreat for three years to study literature and art, depriving themselves of all comforts, including the company of women, for the duration. The pledge survives intact for exactly as long as it takes the beautiful Princess of France (Alicia Silverstone: Batman and Robin) and her three friends -- Rosaline (Natascha McElhone: Ronin, The Truman Show), Maria (Carmen Ejogo: The Avengers), and Katherine (Emily Mortimer: Elizabeth, Notting Hill) -- to travel to Navarre on a diplomatic mission from her father. Fireworks go off the moment they all lay eyes on one another.

"A jest's prosperity lies in the ear of him that hears it," a character here reminds us -- comedy is in the ear of the beholder, basically, and that applies to Love's Labour's Lost. Shakespeare purists will probably be horrified that Branagh, who adapted the play and directed, has juxtaposed the Bard with Berlin... Irving, that is, as well as Cole Porter and George and Ira Gershwin, and has thrown in every cliché of 1930s musicals for good measure. And fans of old musicals may be disconcerted to discover that Branagh has revived this abandoned genre only to turn it into campy fun.

But musicals were always campy, as far as I'm concerned. And however unlikely it is for characters to launch into song in the middle of a movie, suddenly erupting into strains of "I've Got a Crush on You" in the middle of Shakespeare is even more cause for silliness. Yet, in the same way that Shakespeare was profound in his comedic foolishness, so is Branagh. When his lovesick Berowne segues from "And when love speaks, the voice of all the gods / Make heaven drowsy with the harmony" directly into "Heaven, I'm in heaven," well, I just about burst into tears of joy. Irving and all those other great songsmiths were saying the same things as old Will, weren't they?: that men (okay, women too) turn into big mushes when they fall in love, that love and sex and romance are not only fun but a vital necessity of life. Branagh knows that Shakespeare doesn't just live but, punning aside, sings to us still.

Branagh lets a geeky affection for old movies sneak into Love's Labour's Lost, too, from the old-fashioned opening credits to the hilariously parodic newsreels that take the place of Shakespeare's narrators and Greek choruses. Nathan Lane (Isn't She Great, Stuart Little) turns the clown role of Costard into something akin to all the Marx Brothers rolled into one, and there's even a bit of sly reference to that ultimate classic movie, Casablanca.

I see a lot of movies -- a hundred and counting since the beginning of this year alone -- so it's really unusual to find myself surprised by one the way that Love's Labour's Lost continually caught me off-guard, and delightfully so. I love this movie.