Things are looking Up. The buoyant Pixar escapade soars, and our hearts along with it. An optimistic tale about a pessimistic septuagenarian, this lovely film darts unpredictably between comedy and adventure, defying gravity and age.

How much do I love this movie? If it were mathematically possible, I'd give it five stars out of four.

As whimsical as it is fantastic, Up suggests that age is no impediment to daring, nor youth to maturity. It's been a long time since a movie has touched me so deeply while lifting me so high.

Shifting from serious to slapstick to magical, the movie introduces a grumpy old man disgusted with his neighbors - and floats him off to a wondrous anime universe inhabited by a psychedelic cassowary and chatty canines.

Carl Fredericksen is 78. He lives in a patiently restored Victorian surrounded by encroaching development, like a vintage gramophone among iPods. Carl (the sandpapery voice of Ed Asner) is himself a Victorian among millennials, out of place, out of time, and alone. Carl and Ellie, his late wife, always had planned to travel and have kids. Life's script turned out otherwise, but no less sweet.

Without Ellie, the retired balloon vendor with the block head, bulb nose, and Chiclets teeth has become a sourball. Developers want to buy his house and send him off to Cranky Acres or whatever they call those geriatric warehouses that are God's waiting rooms.

Russell (voice of Jordan Nagai), a most persistent "Wilderness Explorer" who resembles an overblown balloon draped with a sash of badges, badgers Carl, wanting to escort him across the street as a means of marking another scouting achievement.

Feeling the weight of the world in his arthritic joints, Carl fastens a mountain of helium-filled inflatables to his roof and drifts toward the heavens. Carl's home airship gives new meaning to "armchair traveler." Oh, the places he goes!

The exhilarating film pays tribute to Buster Keaton's The Balloonatic by way of its slapstick, and to Hayao Miyazaki's Howl's Moving Castle by way of its watercolor palette and traveling domicile. Yet Pete Docter and Bob Peterson's film is consistently original and surprising. Up easily tops the Pixar heights reached by Toy Story 2, Monster's, Inc., Finding Nemo, and The Incredibles.

(No surprise there: Docter directed Monster House and Peterson wrote Finding Nemo. He deserves an Oscar - not just a nomination - for Up's nuanced script that plays the heartstrings and funny bones of those from 5 to 105.)

The filmmakers poignantly tell Carl's backstory in a wordless montage detailing the homebody's loving marriage to Ellie. She was the dreamer who saved pennies for exotic adventures, he the practical one who dipped into the jug on rainy days.

From a repurposed bottle cap that is a sentimental keepsake to a framed picture of a Venezuelan waterfall, every object in their home vibrates with meaning. As he ponders some Big Questions, Carl honors vigilantly the mementos Ellie left behind.

Is there life after a spouse's death? If love can be lost, can it also be found? Is adventure exclusively the province of the young? To these questions Up answers yes, yes, and no, as it follows the childless Carl and his fatherless stowaway, Russell, on a magical journey.

Within 10 minutes the filmmakers have so fully and sympathetically established Carl and Russell that they become as emotionally real as Geppetto and Pinocchio - and as physically specific as the nubby stitches on Carl's knit vest.

Most live-action films selectively focus on foreground or background. Up keeps everything in intense, deep focus - simultaneously juggling hyperrealistic characters and their surrealistic setting. Even without 3-D glasses (I saw the movie in 2-D because 3-D makes colors less vivid) the film is three-dimensional, engaging heart and mind as few movies do.

Dreamers build castles in the air; Carl steers his to paradise. While at first he hopes simply to escape his grief, on his journey he is tested by unforeseen challenges. He has internalized Ellie, and her pluck helps him accomplish feats beyond his dreams, fulfilling hers.

In nine feature films, Pixar animators have detected the souls of inanimate objects (toys, robots) and located high art in low places (a rat/chef). Is it any surprise they could find the adventurer in a couch potato, a housebound old man who, rather than succumb to death, fights for life?

Told with a helium-light wit, Up shares profound wisdom. In effect, it says: When adventure comes knocking, open the imagination. When love comes knocking, open the heart. And when both ring the bell at the same time, come out to greet them with open arms.