The realm is divided between a land of fairies and light, and a land of bog creatures living in the dark forest; Primrose flowers, which are a crucial ingredient to love potions marks the border between the lands. Marianne; a fairy and heir to the throne of the Fairy Kingdom is engaged to be married to Roland; a handsome warrior who breaks her heart when she discovers him kissing another fairy on their Wedding Day. Scorned, Marianne vows to never fall in love again. Sometime later; her sister Dawn, who frequently says she is in love is distraught over the upcoming Spring Ball over which boy she could meet there. Her best friend Sunny, an elf who has a crush on Dawn tries to cheer her up with a song, but they are nearly devoured by a giant lizard before a hardened Marianne rescues them. Sunny, having fallen through the border of the dark forest finds a Primrose petal, which he subsequently hides when fleeing the forest.
At the ball, Roland tries to assert his intention to marry Marianne, who refuses and humiliates him out of the dance. He encounters Sunny and tricks him into returning to the dark forest and have the Sugar Plum Fairy; who had been captured years ago by the Bog King, to create the love potion. Sunny acquires the petal he had hidden and with the help of a curious Imp, ventures into Bog's castle, eventually finding the fairy and promising to free her in exchange for the love potion. Their escape rouses Bog, who manages to recapture Sugar Plum while Sunny escapes followed by the Imp, and Bog is enraged when he learns that Sunny has a vial of love potion. Sunny returns to the ball and tries to hit Dawn with the love potion during his musical number, Bog interrupts the celebrations and captures Dawn just as she is sprayed by the love potion and the Imp steals it, in order to spread it throughout the forest. Bog orders them to deliver the potion to him by Moon Down or he would harm Dawn. Defying her father's order, Marianne flies off after her sister while he grants Roland a small army to head off on foot to Bog's castle. Meanwhile, Dawn falls in love with him due to the potion, and Bog has her imprisoned for his own sanity. Marianne arrives and fights with Bog to return her sister, when she realizes the severity of the situation, the two of them begin to find common interests. When they consult Sugar Plum for an antidote, she explains that true love will negate the effects of the potion, recounting a time where Bog fell in love with a creature in the forest who left him, being in love with someone else at the time he used the potion on her; a fact that she had kept hidden for many years. A mutual attraction begins to develop between the two, but it's only Bog's mother who sees it.
Sunny recovers the potion from the imp and gives it to Roland as they march on the castle. Bog sees this and suspects that Marianne had set him up, breaking his heart again as he leaves her stranded in a spider web. She escapes and joins in on the battle taking place at the castle. Sunny frees Sugar Plum, Dawn (and at Sugar Plum's insistence) the love-stricken forest creatures that imp had hit with the love potion. In the escape, Bog seemingly sacrifices himself by holding the mouth of his den open long enough for everyone to escape. He survives though, to Marianne's relief, and Sunny reveals his true feelings to Dawn, who then reciprocates them, breaking the love potion's spell over her and they kiss to her father's surprise. Roland sprays Marianne with the love potion, who pretends to fall in love with him, only to suddenly punch him and send him off the chasm, being hit by the love potion in the process. Marianne and Bog, at the insistence of Dawn and his mother, finally admit their feelings for each other and kiss while serenading Wild Thing to each other.
- Evan Rachel Wood - Marianne, the protagonist
- Alan Cumming - Bog King, an antihero; later Marianne's love interest
- Kristin Chenoweth - Sugar Plum Fairy
- Maya Rudolph - Griselda
- Sam Palladio - Roland, the main antagonist
- Alfred Molina - Fairy King
- Elijah Kelley - Sunny
- Bob Einstein - Stuff
- Peter Stormare - Thang
- Meredith Anne Bull - Dawn
- Kevin Michael Richardson - Brutus
- Llou Johnson - Pare
- Robbie Daymond - Fairy Cronies
- Brenda Chapman - Imp
- Tony Cox - Plum Elf
- Gary Rydstrom - Angry Gus
A madcap fairy tale musical inspired by “A Midsummer Night’s Dream,” with popular songs from the past six decades used to help tell the tale of a colorful cast of goblins, elves, fairies and imps, and their hilarious misadventures sparked by the battle over a powerful potion. Following the story of two separate kingdoms the magical and the mysterious, when one animal passes the border it starts war between the two kingdoms. The Bog King of the mysterious kingdom realizes there is a potion that can destroy order eager to get it the magical kingdom keeps it from him so that they can maintain peace. Frustrated he kidnaps the princess's sister. Is the only way to get these two sides to get along to use some strange magic.
- This is the fourth animated film produced by George Lucas; the first three being the non-Disney productions 1983's Twice Upon a Time, 1988's The Land Before Time, and 2008's Star Wars: The Clone Wars.
- It also the first among these four productions to be owned by Disney.
- Kristen Chenoweth and Alan Cumming had previously appeared in Annie as Lily St. Regis and Rooster Hannigan, the respective secondary villains.