I suspect that this is why many people despise fantasy. “But it isn’t real! Why should I watch this, when it’s all fake? It doesn’t relate to my life.” Some just shrug off fantasy as silly and irrelevant.

If you see yourself in the above crowd, I can tell you now, you probably won’t like Mirrormask. Unapologetically fantastical, the movie has the organic feel of a garden run completely wild. Its creators, Neil Gaiman and Dave McKean, plotted out the beds, laid the stones for the paths, planted and fertilized the seedlings, and then let it all grow as it would.

Mirrormask could be classified as a children’s movie, with a young lead and themes that will appeal to kids. But it’s not the sort of mindless drivel that often masquerades as children’s cinema. The visual splendor and timelessness of the story will enthrall people of all ages, and no one will confuse the heroine Helena with Lizzie Maguire. Mirrormask successfully combines a child’s fascination with adventure and the unreal and an adult’s fascinations with children growing up.

The movie’s plot is as basic and familiar as they come: a fifteen-year-old girl wants to carve out her own life, separate from her parents’. Just one twist: her parents own a circus, and she’s a performer. All Helena wants is a “normal life,” she tells her mother, right before adding that she wishes her mother were dead. But be careful what you wish for – her mother, Joanne, collapses in the middle of a show the very same evening. Suddenly, Joanne is sick, and the girl is convinced it’s her fault. The night of Joanne’s surgery, Helena goes to sleep and wakes up in Gaiman and McKean’s surreal version of Wonderland.

Shortly after wandering out of what isn’t exactly her apartment complex, she meets the masked Valentine (Jason Barry). The two nearly get swallowed up by a carbon blackness thatis apparently sweeping through the entire world. Predictably, the fantasy realm faces extinction, and our young protagonist quickly volunteers to save it. The Queen of Light has fallen into a coma, and Helena has to find the Mirrormask to wake her and restore balance to this world.

Anyone who has ever so much as looked at the back of a book in the sci-fi/fantasy section of Barnes & Noble could foresee this plot. It’s Joseph Campbell’s classic hero-myth formula. Where this movie shines is not in the originality of the basic storyline but in its execution.

Helena soon discovers that this strange universe is actually the world of her own drawings, a multitude of which cover an entire wall of her bedroom. For the adults watching this film, the story becomes a parable of creativity. Helena brings this world into being with her pen and her mind, and then enters into it to work out her issues with herself and her mother. Through her art, she is able to externalize her internal conflict and see it more clearly.

The young actress playing Helena, Stephanie Leonidas, has appeared in several popular television shows in the UK. Leonidas rescues a role that could easily have been irritating to the extreme and makes Helena sympathetic, even at her most frustrating. She avoids the obnoxious precociousness typical of leads in children’s movies, displaying a believable adolescent combination of childishness and maturity.

Director McKean’s credits include a few TV projects and the covers for Gaiman’s Sandman comics. Personally, I wondered how his mind-bending art would translate to the movie screen. I tend think of animation as either entirely computer-generated or entirely hand-drawn, but Mirrormask combines live-action and CG while also layering in elements of Helena’s static drawings. These techniques produce a wonderfully real-looking otherworld. What you see on screen is a fantasy universe that you can believe in.

The films marketed to kids rarely turn out that way, of course, being generally put together by timid, under-stimulated adults who make the characters speak in the stilted rhythms of sitcoms and are decades out of touch with the fairytale logic of youth. MirrorMask, a gorgeous flight of the imagination, gets the recipe blissfully right. Drifting through a visually astounding dreamscape, it’s an Alice in Wonderland for the 21st century.

Adolescent Helena Campbell (Stephanie Leonidas, Yes) is fed up with a constant diet of fantasy. She wants to quit juggling, leave her parents’ traveling circus and join the world of normal people. Helena is actually struggling with herself: While she rejects performing for her mom and dad, she is in fact extravagantly gifted with imagination, covering her bedroom walls with fantastic characters and landscapes, and putting on sock-puppet plays in which her feet battle for supremacy.

When her mother is hospitalized in a coma after another argument with Helena about leaving the carnival, the distraught girl falls into a fitful sleep and awakens to find herself in a parallel world that is a distorted reflection of her own existence.

The new dimension is more colorful than daily life, rendered in spicy orange, sensual gold and passionate red, but it also has deeper shadows and stranger inhabitants. There are sphinxes and a gryphon, bird-gorillas, singing robots and mechanical spy-spiders that shadow Helena as she seeks a talisman that will revive her mother and the Queen of Light, a dreamworld doppelgänger who has also fallen into a deep slumber.

To add urgency to her quest, Helena discovers that a mean-spirited version of herself has replaced her in the everyday world and is destroying the portal connecting the two dimensions to strand Real Helena in fantasyland. As she goes, Helena learns that it’s vital to be able to believe in absurd, impossible things, such as hope.

Writer Neil Gaiman and illustrator-turned-director Dave McKean, longtime collaborators in publishing, have created a remarkable film, a cornucopia of digital effects that never feel forced or unnecessary. McKean composes his frames with impressionistic grace, while Gaiman provides a framework loose enough to encompass our own imaginative contributions to the story.

Based on Neil Gaiman’s fable, MirrorMask’s Alice is an exceedingly clever young woman named Helena. A teenager who is miffed at her parents, she’s fretting over her critically ill mother when she slips into a dreamland and has to solve a series of surreal puzzles that all have something to do with learning to make smart choices and helping her mother get better. “I hate feeling so helpless,” says Helena, a feeling most of us can relate to, but the movie is the story of how Helena learns when she must accept helplessness and when she has to fight it.

Stephanie Leonidas, as Helena, and Gina McKee, as her mother, make sure the movie’s emotions are grounded in the real world, but MirrorMask’s inventive dreamworld is equally involving, with giant puppets that resemble Minneapolis’ In the Heart of the Beast Puppet and Mask Theatre, a massive library where winged books flap right off the shelves like birds and a loopy dog/man who likes riddles.

The work of novelist, comics scribe and cult god Neil Gaiman and artist Dave McKean (they cowrote; McKean directs), this English-made oddity is a dazzling, surrealist concoction full of talking sphinxes and flying books, bizarro penguins, ooky one-eyed spiders, beautiful ink drawings that spring to life, and creatures of all stripes and sizes that look as if they were sculpted by Dalí, or Bosch, or a kid with a really warped imagination.

Which is what Helena (Stephanie Leonidas, looking like a young, punky Helena Bonham Carter) is. A juggler, an artist, and a reluctant member of her parents’ circus troupe, Helena tumbles into a deep, dark dream after having a fight with her mum (Gina McKee) and then hearing that Mum’s in the hospital, awaiting surgery.

Various characters from her waking life (like Dad, played by Rob Brydon) show up in Helena’s slumberville, sporting masks and fancy costumes, intermingling with computer-generated creations on a whooshy, collage-like screenscape.

But it’s also a 30-minute idea wrapped in a 100-minute movie. It’s a jewel box filled with cubic zirconia.

Writer-director Dave McKean’s fantasy, produced with the help of the Jim Henson special-effects people, is designed to within an inch of its life. He even designed his lovely, 21-year-old star, Stephanie Leonidas, to look like the punk-period (late 1980s) Helena Bonham Carter of Getting It Right.

Leonidas’ character’s name? Helena.

Helena is a circus teen. Her family runs one, a menagerie of jugglers, clowns, mimes and a high-wire artist, her mom, played by Gina McKee of Notting Hill. Helena is a talented juggler with a serious artistic bent. And she has had it with living her dad’s dream.

Let other kids run away to join the circus, she says. “I want to run away and join real life!”

Mom passes out after a heated argument and a performance. Dad (Rob Brydon) is trying to save the circus, and Helena is wracked by guilt. That guilt, and the drawings of her fevered imagination, spill over into a long night’s dream.

It’s a shadowy, monochromatic world of competing towns, a city of light and a city of shadows. Mom is recast as the white queen and the black one. Ms. White has fallen into a deep sleep. Helena goes on a quest for the talisman or charm that will revive her, a mirrormask.

“We wake the queen and save the world,” she says to her masked sometime-sidekick, Valentine.

It is a dream of digital griffins, sphinxes and hairy, face-sucking spiders, most of whom are rendered in a murk so dark you can’t make out all their digital details.

She fetches The Really Useful Book, full of advice to “Remember what your mother told you” and “Say you’re sorry” and the like.

And she does, and never ever does that sexy-cool wisp of her hair flopped over one eye slip out of place.

The dream trip is an hour long, and only fitfully amusing amid the flood of images.