The Trix return to Cloud Tower. Griffin gets angry at them, as they are not to set foot in Cloud Tower again, but since they have the dragon fire she is unable to do anything to them. After almost killing the other witches, the Trix defeat Griffin, with Icy freezing her, and take over Cloud Tower.
Bloom and Stella return to Alfea and meet up with Flora, Tecna, and Musa before Griselda appears, but is nice to Bloom and gives her tea in Faragonda's office to make her feel better. Bloom tells Faragonda that she is the princess of Sparks and that Daphne hid the dragon fire inside her. Faragonda says she suspected as much, but didn't tell Bloom because she believes the truth comes to people when they are ready to hear it. Bloom says she wasn't ready to hear it as she did from the Trix, and that they took the dragon fire to summon a magical army. Faragonda and Griselda realize this is the Army of Decay.
Imprisoning Griffin and the other teachers of Cloud Tower, the Trix declare their plan to unleash the Army of Decay.
Bloom wishes she never discovered her Winx or came to Alfea. Sky tries to call her but she and Stella refuse to talk to him. When Riven goes to tell the Trix this, Darcy breaks up with him now that they have the dragon fire, and the Trix attack him. Then they summon the Army of Decay, consisting of many kinds of zombielike creatures. Knut doesn't like them.
Dark rainclouds appear and the Army of Decay try to break into Alfea. The Winx transform to fight them, alongside the other fairies. Stella and Musa destroy them with regular attacks, and Flora summons a killer plant that eats many of them. Bloom is able to stomp the buglike ones, but then the bigger monsters attack.
Palladium destroys a monster attacking Bloom, and Wizgiz turns into a dinosaur to crush some of the monsters. Griselda is impressed with the students' fighting the monsters, and Saladin tells Faragonda of the battle at Red Fountain.
Diaspro arrives at Red Fountain with some of her guys and destroy more monsters. She says Red Fountain will fall to the endless army and wants Sky to go with her, but he says his place is at Red Fountain, his friends need him, and if Red Fountain falls, he'll fall with it.
The Trix plan first to take the realm of Magix, and then the universe.
- The Trix take control of Cloud Tower and summon the Army of Decay, which attacks Alfea and Red Fountain
- Darcy breaks up with Riven