The brainchild of writer-musician-director Mathias Malzieu, "Jack and the Cuckoo-Clock Heart" began life as both a 2007 novel called "The Boy with the Cuckoo-Clock Heart" and a concept album from Malzieu's French rock band Dionysos. This computer-animated feature film adaptation, co-directed by Stephané Berla, is unusual and sublime, a fairy tale of exquisite beauty and gentle, poignant poeticism. If some of its themes involving love, sacrifice and mortality may go over the heads of younger viewers, they still likely won't be able to turn away from its intoxicating spell. As for everyone else in search of those rare animated releases that break new ground, play by their own rules, and stand apart from the pack, they will find exactly what they've been looking for with "Jack and the Cuckoo-Clock Heart."

On the coldest day of 1874, Jack (voiced by Mathias Malzieu in the French-language version and Orlando Seale in the English) is born with a frozen heart at the cliffside home of childless midwife Madeleine (Marie Vincent and Emily Loizeau, Barbara Scaff). A crafty inventor, she makes him a cuckoo clock to replace his failing heart. His new lease on life and delicate condition come with three stipulations, the most crucial being that he should never, under any circumstances, fall in love. Abandoned as a newborn by his birth mother, Jack grows up under the loving, cautious care of Madeleine. Sheltered from the outside world all his life, Jack is finally given permission to explore the town of Edinburgh on his fourteenth birthday and meets the bewitching, nearsighted, equally lonely Miss Acacia (Olivia Ruiz, Samantha Barks).

When a terrible accident occurs—Jack's cuckoo pokes out the eye of school bully Joe (Grand Corps Malade, Harry Sadeghi)—the young boy must leave home. His travels lead him to a friendship in Paris with future filmmaking pioneer Georges Méliés (Jean Rochefort, Stephané Cornicard), a scary run-in with a scalpel-wielding Jack the Ripper (Alain Bashung, Howard Samuels), and finally to a carnival/sideshow park called Extraordinarium where he discovers Miss Acacia is working as a flamenco singer and dancer. With his very life in danger if he allows his artificial heart to feel love, Jack faces the toughest decision he's ever had to make.

"Jack and the Cuckoo-Clock Heart" is idiosyncratic bliss, obviously more unconventional than an American-made studio animated release, but also far more curious and compelling. Directors Mathias Malzieu and Stephané Berla have mounted a film that does not pull any punches—a child is nonchalantly chloroformed early on, and there are passing lyrics sung about ripping another's clothes off "like confetti"—but within its off-kilter sensibilities is a playful, quirky sense of humor that keeps it from ever appearing untoward. The passion and care they bring to every frame is in immediate evidence, from the snowy vistas of Edinburgh to the dusty, proudly anachronistic snapshots of a pre-20th-century midway. A trip on dark ride/rollercoaster combo called The Ghost Train, full of supernatural visages, a performing rock band, and a tunnel of creepy bunnies, is a showstopper. Meanwhile, Dionysos' songs will have viewers humming them for days, even weeks, after, while the romantic existential finale is as gentle and provocative as it is emotionally transcendent. Joyous and mournful in equal measure, "Jack and the Cuckoo-Clock Heart" tells of a boy who must learn all too quickly how beautiful yet bitterly temporary everything is in life. This is a special gem of a movie.