“Epic” means big — usually a big story filled with grand adventures. This is a grand adventure, but the story is very small, or at least its characters are. Like “Honey I Shrunk the Kids,”  “A Bug’s Life,” and “The Ant Bully,” this is a story about the tiny creatures who live in the forest, riding on hummingbirds and swinging swords the size of toothpicks.

They are so little and move so quickly that most humans cannot even see them. But there is a scientist named Bomba (Jason Sukeikis) who knows they are there. He is so obsessed with tracking the little creatures that he lost his wife and daughter. Everyone thinks he is crazy.

As the movie begins, his ex-wife has died and his now teenaged daughter MK (Amanda Seyfried) is arriving. She has had almost no relationship with him and is not sure she wants one now especially when she learns that he still insists that there is a community of tiny beings in the forest. He has rigged up motion-sensitive cameras and he keeps detailed records of his sightings. MK decides to leave, but on her way out she has a close encounter of her own and suddenly finds herself shrunk down to the size of an insect and with the dying queen of the forest (Beyoncé Knowles) giving her custody of a magical bud.  If the bud is not exposed to moonlight at exactly the right once-in-a-century moment, the forest will fall into the hands of the evil Boggens, led by Mandrake (two-time Oscar-winner Christoph Waltz).

In the forest, there is a constant struggle between the forces of life and decay.  The queen is protected by an army of Leafmen, led by Ronin (Colin Farrell).  Ronin is responsible for Nod (Josh Hutcherson), the impetuous and rebellious son of a close friend who died in battle.  Nod quits the Leafmen in frustration, but when everyone is needed to make sure the magical bud gets to bloom in the moonlight, including Ronin, Nod, MK, and an adorable snail and slug duo (Chris O’Dowd and Aziz Ansari, the comic highlight of the film).

The co-producer, co-writer, and production designer is the brilliant writer/illustrator William Joyce, inspired by his book, The Leaf Men.  The visuals are pure magic, from the grand sweep of the forest to the tiniest details of the saddle on a hummingbird.  Every shot is filled with marvelously imaginative ideas, exquisitely rendered.  MK’s absent-minded scientist father has a wonderfully messy office filled with charts and equipment and record books that have a slightly stem-punk, Victorian feel.  Chase scenes through the trees are deliciously vertiginous in 3D.  And the quiet moments are lovely, too, with MK and Nod sharing the experience of losing a parent and learning to appreciate the families they have.

Parents should know that this movie includes a discreet but sad death of the murdered queen and references to divorce and the death of parents.  Mandrake’s son is killed, and characters are in frequent peril.  There are some scary images and characters use brief strong (for PG) language.  There is one sweet kiss.

Family discussion: “Who gives up everything for a world that’s not even theirs?” What does it mean to say “many leaves, one tree?”

If you like this, try: “Robots,” “Ferngully,” and “A Bug’s Life” and the books by William Joyce.