Based on a short story by the great Irish American author F. Scott Fitzgerald, "The Curious Case of Benjamin Button," opening on Christmas Day, is one of the most courageous and haunting big budget films to come along in years.

This is film making the way they used to do it in the golden age of Hollywood, on a grand scale, featuring a flawless cast and featuring a remarkable storyline.

It begins in New Orleans in 1918, when a child is born with an 80-year-old's body. Benjamin Button ages backward, growing younger through the years, reversing the natural cycle and making his whole life a remarkable back to front adventure.

Born to a young Dublin girl who dies soon after, Benjamin's father is maddened by grief and horrified by his ancient-looking newborn son. His first thought is to throw the child into the nearest reservoir, but he relents, abandoning the boy at an old folks home where a kindly nurse who raises him as her own takes him in.

"He's a miracle," says the nurse Queenie, played by the gifted character actress Taraji P. Henson. "He's not the kind of miracle that you pray for I know, but he's a miracle just the same. He's still a child of God."

Brad Pitt, as Benjamin, gives the performance of his career as the young soul trapped throughout in a pensioner's body. Naturally enough, few people can emphasize with Benjamin's predicament until he meets Daisy, a local girl who looks beyond his wizened features to the little boy within.

So begins one of the most unusual and affecting love stories you'll ever witness.

As Daisy, the impulsive and beautiful young woman that Benjamin falls for, Cate Blanchett is perfectly cast. The challenge to the girl is as interesting as the challenge to the actress - she has to grapple with the unexpected complications that arise when your lover keeps growing younger as you mature.

Only in exact middle of their lives are they briefly at the same age, and for that reason their love affair finally blooms, but only for a little while because time - the film sorrowfully keeps reminding us - is inescapable, as it catches up with everyone and everything.

Pitt and Blanchett are revelations in their roles.

Pitt makes his unusual backwardly aging character a watchful observer of his own life, stepping back from each event he lives through with a writer's detachment, at once inside and outside the frame.

And Oscar winner Blanchett has never been better. Her slightly stricken expression, in a scene where she must finally accept that she can neither stop or store the passing of time, is one of the most quietly moving moments you'll ever see in film.

Hollywood rarely tackles the theme of the impermanence of life with this much courage or poetry. The film is not perfect - there are scenes that are sentimental and strained - but at its core is a simplicity that can't be denied.

At its best, the film literally sweeps you up. It's magically paced, thrilling to look at and the leading performances are easily among the strongest of each actor's careers.

Tilda Swinton, as the British woman that Benjamin has a brief and memorable affair with, deserves an Oscar for her supporting role. She's a major star in a vehicle that's finally worthy of her prodigious skills.

"While everyone else was getting older," says Benjamin, "I was getting younger - all alone."

Knowing that Daisy can't possibly cope with raising one child as her own husband heads slowly toward childhood himself, a day finally comes when they both have to make a painful choice. Neither they nor the viewer will want them to part, but time waits for no one, not even Brad Pitt and Cate Blanchett.

"The Curious Case of Benjamin Button" sends you reeling into the street when it's over. Don't be surprised if you want to call up someone you love to tell them so after it ends.

The message of this stately, haunting film is that - despite what you think, or what you hope - it will all end, and soon. Every moment rushes headlong into nothingness, and all that remains is how you felt about it.

And that's enough, actually, if you lived well.