"The Last Unicorn," the animated film currently at a number of area theaters, is faithful to the mystic heart of the cult classic that inspired it; that's probably because Peter S. Beagle adapted the screenplay from his own book.

Like "The Secret of NIMH" earlier this year, "The Last Unicorn" is a treatise on mortality, magic, heroism and faith couched in ecstatic imagery and accessible characters that speak to the needs of the viewer. In other words, there is enough action and general movement to satisfy younger moviegoers and enough gentility and creative thought to please everyone else.

The story follows the Last Unicorn as she seeks to unravel the myth of her species' disappearance even though it means abandoning the inherent safety and quietude of her forest. She refuses to accept that she is the last, and inspired by a butterfly who assures her that "you can find the others if you are brave," the quest begins.

There is a frightening premonition of a fire-coated red bull that has hunted all the other unicorns down and "passed close behind them, covering their footprints," leaving a vapor trail of doubt so that men no longer see unicorns and no longer believe in them.

As in any good quest, the Last Unicorn encounters helpmates -- the bumbly Schmendrick the Magician and heart-of-gold Molly Grue -- as well as enemies, including the wicked, witchy Mama Fortuna who captures the unicorn and imprisons her in a circus of "fellow legends" -- the manticore, the satyr, the dragon and the harpy. Schmendrick helps the unicorn escape despite his errant magic.

Soon, they meet up with the red bull and the unicorn is protectively transformed to a human shape, Lady Amalthea. Inside a dark castle she finally encounters the ultimate evil of King Haggard and the redeeming hope of his son, Prince Lir. The prince, of course, falls in love with the lady. The pieces begin to fall in place, the battle lines are drawn: Lady Amalthea faces a momentary crisis of conscience and confusion while the prince realizes she cannot be won by great deeds but only by great dreams. In the end there are true wizards and heroes, a domestic denouement and a bittersweet epilogue. As someone says, "There are no happy endings because nothing ends."

Some of this is heavy going for an animated feature, but "The Last Unicorn" operates on so many levels that one can take out whatever one puts in. It is ultimately a fragile fantasy that has been treated well "in translation," certainly much better than Ralph Bakshi's "Lord of the Rings." But a major conflict arises out of the disparity between a sophisticated script and stunning vocal performances and the rather simplistic animation. On the down side, backgrounds tend to be flat and static and the character movements are more cartoony than animated. "

However, the voiceovers are superb, particularly Mia Farrow as the mystically plaintive unicorn/Amalthea, Alan Arkin as the self-effacing Schmendrick, Tammy Grimes as the worldly dreamer Molly, and Christopher Lee as a sufficiently dread King Haggard. Jeff Bridges as Prince Lir is a mite Saturday morningish while Angela Lansbury is clever but predictable as Mama Fortuna. There are also some delightful cameos, including Robert Klein as a butterfly with a song for every emotion, Paul Frees as a peg-legged, eye-patched pirate cat and Rene Ouberjonois as a hilariously grotesque speaking skull. The red bull doesn't speak, but he is a truly terrifying vision.

The movie makes for a warm and moving experience but it should have been a shatteringly ethereal one, a fairy tale speaking to unanswered dreams and the powers of imagination, friendship, will and hope. Luckily, there's always the book to go back to.