The book begins with the same narration from the movie but when the Enchantress began her spell, something went wrong. The spell does affected not only the castle but the entire forest surrounding it! The magic increased dramatically becoming stronger and while the Enchantress tried to stop it, it is draining her magic and lifeforce. Belle, while looking for her father Maurice in the forest, came to help the dying Enchantress, and because of her kind heart, she gave Belle a magic rose to fix the magic. Thus, Belle became a mage, studied all of the books in the Enchantress' library to see if she can restore her universe, only with healing and purification magic.
Now, in the village, there's a wall build by Maurice to "prevent" the magic coming in, but it was temporary as some bit of magic managed to slipped through, affecting plants and small animals. However, certain people were affected and transformed who went outside the village: Maurice, who is now a beaver and Le Fou, who is a toadstool. Belle went to the bookstore to find more information of restoring the magic but noticed that the owner disappeared and the shop was closed. She was then greeted by Gaston, who is this universe, is now a royal huntsman. Gaston revealed that the bookseller is outside of the village. Belle immediately began to search for the bookseller who is now a crow. After finding the crow, she stumbled upon two strange objects: a footstool and a chipped tea cup (Guess who?) with a creepy message on the ground that said "Help Us". She then took the objects to Maurice who is currently in the Enchantress' library. They found out that the objects belong to the Royal castle. Maurice, gave Belle a staff that can hold her magic rose for better mobility and light (which is currently, her magical staff in the game).
Belle began to search for the castle, while stumbling upon more objects and cryptic messages and dark creatures to defend and purify. She was reunited with Gaston who found her book that she dropped when looking for the bookseller. As she didn't enjoy his company, Belle leaves him until she came across Monsieur D'Arque as a walking tree (if you don't recognize the name, he's the owner of the asylum that Gaston hired to take Maurice in after he came back to the village to warn them about the Beast that "held" Belle captive in the castle in the movie). She tries to restore him but it did not work and they fight, with the Monsieur revealed that the people transformed in the forest because of fear. Belle managed to subdue the Monsieur by summoning rose bushes. Gaston then approached Belle, remarked about her magical abilities. He then deduced that bravery help them without transforming, although Belle found that hard to believe and wondered if the Monsieur's theory is true. Reminded of Gaston's title, she reluctantly asked him for assistance of locating the castle.
The pair managed to reach the castle and was "greeted" by Lumiere, in human form but rarely talked. Lumiere led them to the ballroom, where a "magical ball" occurring. The magic transformed Belle into her iconic ballroom dress, much to her dismay, and Gaston in his outfit when he was trying to marry Belle at her home in the movie. With Gaston to create a distraction to boast his accomplishments, Belle then located a muted Mrs. Potts, which then led her to the Prince (Adam), who is not excited to see her. He then asked her to dance. Belle began to ask questions in which Adam kept dodging them. She immediately knows that the magical ball is an illusion that then dispel in which made Adam angry and left to head for the West Wing. Belle immediately followed the Prince, but noticed her rose reacting strangely. She then saw Lumiere who bowed and offered her hand, which lightly burned her finger. Lumiere began to melt, asking Belle to help the Prince. Adam in his room watching the scenes through the Magic Mirror, checking for any changes by Belle. Belle then found the Prince, the Magic Mirror and another magical rose (the same one from the movie, but in full bloom without any petals falling).
Adam began to tell his story: the Enchantress casted the spell but stated he passed the test and became the master of the mirror and his rose to protect everyone in the castle from the magic, though Belle sees through the lie as this was also an illusion as most of the people left the castle and the mirror was suppose to show Adam what was happening in the village, the woods and the castle. The Prince then summon gargoyles to take Belle back to the village but then Belle used her magic to defend herself and show the Prince the truth, a reflection of the Beast. Adam then stated the spell did happened but in his heart, he didn't want the others to be cursed as well. He believed that his wish had stopped the curse but it happened anyway as he stated that the transformation started slowly and the others became more of lifeless objects. He them blamed himself that everyone ran away because he was acting "like the Beast" but Belle stated that everyone was trying to help him away from the burden of loneliness. The Prince then started to a pre-matured transformed state until D'Arque entered the castle.
We then found out that Gaston hired and helped D'Arque to capture certain villagers and made sure they stay in the woods and he can perform heroic deeds. He then revealed he locked Maurice outside the wall so he can transform. They also wanted Belle and Adam's power to amplify the wood's magic as they are similar. Belle fought Gaston and D'Arque but went back to the Prince for assistance. When they about to use the Magic Mirror, Gaston, consumed by D'Arque, grabbed it and began to see grand illusions of his desires and wishes, however the illusions faded as a shadowed Beast appeared on Adam. He then attacked Gaston and retrieved the mirror to use its magic. It initially failed as he still sees his Beast reflection. Belle used her magic to seal and break the mirror's illusion which made the Prince transform into the Beast. The Beast then fought off D'Arque as Belle used her magic to heal the entire castle, woods and village. Everyone was turning back to normal, mostly as the original spell to the castle is still active. Though Gaston survived, Belle wanted to heal him, but he's now seeing the Beast as a monster. D'Arque then grabbed Gaston and lured him back to the woods.
As the original curse is still active, Belle and the Beast tried to figured out why the Enchantress's spell went out of control in the first place. When about to head to the library, they heard a voice from the stained glass. Mickey Mouse appears and he wanted to recruit both Belle and the Beast as Guardians.