With Bloom having trapped Acheron in the Infinity Box and traded it to Rumpelstiltskin for the Legendarium Key, she now finds herself having to deal with the Trix before she can leave the Legendarium and rejoin the rest of the Winx, who are still in combat with the Great Lizard Spirit conjured by Acheron before he pursued Bloom into the Legendarium world.
Luckily, Selina remembers the dragon skeleton that contains all the magic she stole while allied with the Trix and Acheron inside Cloud Tower and using a spell with her witch magic, she destroys the skeleton, restoring the magic to its rightful owners, and fully gaining the trust and support of the Winx in showing she's seen the error of her ways and turned good again as the return of the stolen magic destroys the Great Lizard Spirit as well. Though they have won their fight, Bloom is still trapped with the Trix in the Legendarium.
Despite Bloom's best attempts to fight back, the Trix soon disarm her of her Mythix wand, then trap her in their Cage of Sorrow, taunting her that they will always be there to kick her and the rest of the Winx's butts, but remembering her friends and family, it gives Bloom the strength to break out of the Cage of Sorrow, sending the Trix flying in the process, before Bloom calmly traps them in bubbles of her own, retrieves her Mythix wand, and leave the Legendarium world, even as Icy swears Revenge once more for being defeated by the Princess of Domino and keeper of the Dragon Flame.
Once outside, it is revealed that only Selina can lock the Legendarium for good with the Legendarium Key, and despite Icy and the other Trix pleading for Selina to reconsider, Selina has seen the error of her ways siding with Acheron, and locks the Legendarium for good, trapping the Trix inside forever.
Back on Domino, Selina returns the Legendarium to Eldora, then asks to become her student again. The Fairy Godmother accepts taking Selina back under her tutelage, much to Bloom's happiness to see her old friend back as a fairy once more. As for Cloud Tower, Prof. Griffin returns to her position as Headmistress, and on Domino, the Winx attend the wedding of Bloom's big sister Daphne and her husband-to-be, Thoren. After the ceremony, the Winx and everyone sees Daphne and Thoren off as they depart on their honeymoon, concluding the season.
This episode provides examples of:
- And I Must Scream: The Legendarium is locked for good with the Trix still inside it, leaving them to be stuck there forever as fictional characters.
- Anti-Climax: Given Acheron has wasted in the previous episode, the Trix are the ones facing Bloom. They destroy Bloom's Mythix's wand and trap her in the Cage of Sorrow, only to break free, defeat the Trix, and escape the Legendarium despite her wand getting destroyed.
- Big "NO!": Icy screams one when Selina locks the Legendarium for good.
- End of an Age: This is the last episode to be dubbed in English by Atlas Oceanic Sound and Picture.
- End-of-Series Awareness: The episode's title itself alludes to this is the last episode of the Nick dub, before DuArt took over.
- How Did We Get Back Home?: Bloom traps the Trix in the Legendarium's Pocket Dimension. It's explicitly stated there's no way for them to come back now that the aforementioned book has been sealed forever. Yet, they appear mid-season seven just like that.
- Only the Chosen May Wield: Selina is the only one to turn the key and lock the Legendarium, hence she opened it in the first place.
- Sealed Evil in a Can: The Trix were still in the Legendarium when Selina locked it for good, and they're stuck there as fictional characters.
- Speak Now or Forever Hold Your Peace: Eldora gives this at the wedding. Naturally, no one objects.
- Wedding Finale: The episode, and the season, ends with Daphne and Thoren getting married.
- Wham Episode: Selina has locked the Legendarium for good with the Trix trapped inside it and has undergone a Heel–Face Turn, and Daphne gets married to Thoren.
