There’s a big party in Domino: Bloom just can’t wait to finally hug her beloved sister Daphne again. The Winx, the Specialists and all the people from Domino welcome the new princess with great joy!
Daphne’s new life is soon very busy ... Faragonda summons her to Alfea to become the new teacher of History of Magic. What a big joy for Bloom!
Meanwhile in Cloudtower, there’s a new talented student. The young witch Selina shows everybody her power: she is the only one to be able to control the Legendarium, the book in which the powerful sorcerer Acheron has been trapped for so long! Under his influence Selina can turn the monsters of the book into terrible reality!
When the Trix realize how powerful she is, they decide to form an alliance with Selina: their plan, this time, is to conquer all the Colleges of the Magic Dimension.
In Lynphea, Selina evocates a flying dragon that attacks the Winx! During the fight, the fairies lose their powers, but luckily the Specialists protect them with the help of two Paladins: Thoren and Nex.
Bloom gives generously part of her power to the Winx: thanks to her, they get the Bloomix power! Their journey can finally continue ...
Daphne finds out that the only one who can help them in this mission is the Fairy Godmother Eldora: she, in fact, was the guardian of Legendarium for long time and she knows how to close the evil book once and for all. But where is she? In Egypt, perhaps...
After touring the world in search of Eldora, Bloom and the Winx finally find out that she is ... just in Gardenia. The Fairy Godmother reveals the girls the secret to close the Legendarium: they must forge a key made of magical items ...
Travelling in legendary places on Earth, and using Mythix wands donated by the fairies of Tir Na Nog, the Winx find the two elements that serve to forge the Key: Emerald of Fantasy and Silver Spear.
For the Winx, finally, some good news: the Legendarium Key is ready! But closing the powerful artifact is not an easy task: the Trix, in fact, have made Cloud Tower invisible!
But the troubles keep coming: the dwarf Rumpelstiltskin is immune to magic and steals Musa’s voice. The wicked creature proposes an exchange: the Legendarium’s key in exchange for the voice of the fairy of Music ...
The big day has come! Daphne is going to marry her beloved Thoren, but suddenly… Acheron is set free! It is terrible: the magic disappear from the Magic Dimension in a blink of an eye!
Thanks to the Dragon Flame donated by Bloom, the Winx fly to Cloudtower to face the evil sorcerer. The only good news is that the Trix are finally trapped inside of the Legendarium forever!
In a no holds barred duel, Bloom traps Acheron in a magic box, and proposes an exchange to Rumpelstiltskin: the sorcerer in exchange for the Legendarium Key!
Selina feels sorry for what she has done and closes the Legendarium once for all! The Key is now in the safe Eldora’s hands and the bad guys are trapped forever!