Pixar takes a bit of a risk with an unlikely hero in its newest release, Up.

An old man with most of his life behind him, Carl is crabby and isolated. He's not your average cute animal, beautiful princess, or fast machine we so often see at the heart of animated family films. But Up, releasing in theaters on May 29, 2009, works on every level. It's funny and poignant in equal measures, in no small part because the character and the story are so unpredictable.

Carl (voiced by Ed Asner) has lost the love of his life, Ellie. She had shared with him a love for life and a longing for adventure. A wordless musical montage, as moving as any film segment you'll see this year, sweetly and gently takes us through their courtship, marriage, and Ellie's final illness. Carl is now an old codger, pestered by the construction company which wants his land, the retirement home workers who plan to take him away, and a Wilderness Scout who wants to earn a badge for service to the elderly. Carl merely wants to be left alone, but life still goes on around him. An unfulfilled promise haunts him along with the absence of his beloved wife, a promise he made in childhood to take her to an idyllic waterfall in South America.

"We were experimenting with a lot of escape kind of ideas, and this floating house was just very poetic and interesting and appealing," said Pete Docter, director of Up. "So we put the grouchy guy in the floating house with balloons."

With no family to care for, Carl thumbs his nose at all the world and its demands. He attaches balloons to his house and floats away, headed for South America. The Scout, Russell (voiced by Jordan Nagai), is a most startled and unwelcome stowaway.

The unlikely duo finds plenty of new trouble in South America. Russell befriends a large, loud bird which he names Kevin. This particular bird is the desired prey of an old adventurer, Charles Muntz (voiced by Christopher Plummer), and his pack of mouthy but vicious dogs. The dogs are equipped with collars that translate their thoughts into English. Aside from a natural canine obsession with squirrels, their thoughts are rather sinister. One Labrador named Dug (voiced by Bob Peterson), is more of a lover than a fighter. He adopts Carl as his new master, much to Carl's chagrin.

The result is lots of canine capers, high-flying adventures, and perhaps the slowest fight between two old fogies ever recorded on film.

Pixar's successes have become legendary. Toy Story. Monsters, Inc. The Incredibles. CarsRatatouille. Wall·E. Now that Pixar has joined the Disney family in recent years, some have wondered if the magic will continue to remain. Up lays those doubts to rest. Like its predecessors, Up delivers laugh after laugh, and not just small chuckles, but big sidesplitting guffaws. These are done with clean, gentle humor that is safe for children. Also following Pixar tradition, it delivers a few lumps in the throat as well. Carl and Russell both need connection with another human being. Both have suffered real loss, and their eventual friendship echoes the poignancy of those losses.

"The [movies] that I find that stick with me are the ones that have a deeper kind of emotional resonance," Docter said, " We're always trying to find those kind of hooks in our movies even though the film might be about bugs or fish or monsters, that there's some identifiable relatable thing that we see in our own lives that these characters on the screen are going through and that's certainly what we were after with Carl."