Centuries ago, an evil and sentient force known as the Forbidden Arts emerged from the underworld, aiming to annihilate all rivals for magical dominance on Earth. During this time, a community of uniquely large and talking flying squirrels called scullions formed an alliance dedicated to locating and destroying the Swan Princess. When Odette, the Swan Princess, was born to King William, the Forbidden Arts tried to manipulate a sorcerer named Rothbart to defeat her. However, Rothbart was killed by Prince Derek, thwarting their plans.
In the present day, Odette and Derek are under pressure from Uberta, the royal advisor, to have a child of their own. Unbeknownst to them, they are being tracked by two of the most cunning scullions, Cutter and Jojo, both brothers and Master Trapmakers. The Forbidden Arts teams up with Mangler, their leader, but expresses frustration after a recent failure. Angered, the Forbidden Arts attempts to set Odette on fire, but her inherent power prevents them, forcing them to retreat to their crystal cave to recover. Meanwhile, a nearby house is set ablaze, tragically resulting in the murder of a young girl named Alise's father. Odette and Derek bring Alise to the castle, and Odette feels a special connection with her, as both have lost their fathers. Though Alise initially remains silent, she gradually bonds with Odette and Derek, leading the couple to decide to adopt her, as she has no other family.
The plot thickens when the scullions launch a vigorous attack on Uberta's castle, kidnapping Alise to lure Odette and Derek into a trap. They manage to evade the scullions' deadly traps, but Derek is poisoned by Mangler's blow dart in the process. Fortunately, a friendly scullion called Scully heals Derek with an antidote and shares crucial information about the legend of the Swan Princess and the true villain—the Forbidden Arts. Scully also reveals that he has been safeguarding a magical stone, and the group, now united, sets out to rescue Alise.
During a daring distraction orchestrated by Derek, Scully infiltrates the scullion village and finds Alise trapped inside the Forbidden Arts' cave. Despite his efforts, he cannot rescue her immediately. Meanwhile, Odette confronts Derek when he is captured, explaining her primary wish is for her loved ones' safety. Scully then exposes that the legendary story of the Swan Princess is a lie, and instead, the real threat is the Forbidden Arts. As the villains try to eliminate Odette with a poison dart, Jojo, the younger brother, intervenes by blocking the attack. Odette cures him with an antidote prepared by Scully, and a tablet containing a corrupted prophecy is recovered, revealing the true destiny of Odette.
At the castle, Uberta and Lord Rogers face punishment at the hands of the scullions for protecting Odette. They bravely declare their love for each other. Armed with the real prophecy tablet, the scullion army joins forces with Derek, Puffin, Jean-Bob, and Speed to safeguard the magical stone. Despite their efforts, the Forbidden Arts manages to obtain it, gaining immense power.
The climax unfolds when Odette and Scully enter the Forbidden Arts' cave to rescue Alise. They are attacked by Mangler, but Scully heroically defeats him, though Odette remains unable to free Alise from her prison. At this pivotal moment, Alise finally speaks, urging Odette to destroy the Forbidden Arts' crystal. Unable to do so herself, Odette watches helplessly as Scully sacrifices himself by jumping onto the crystal to destroy the evil once and for all. His selfless act triggers a massive explosion that frees Alise, who calls out to Odette, saying "Mommy" with trust and love.
The movie concludes with a joyful celebration of Alise's presentation to the kingdom, symbolizing hope and new beginnings. A statue of Scully is erected in the castle's garden as a lasting tribute to his bravery and sacrifice, reflecting the enduring power of friendship and courage amidst darkness.
