The Trix decide to send energy into Cloud Tower to give them full control and make it give them the codex.
Griffin tells the Winx to find the Trix before they take control of the tower. She gives them ruby coins that light up whenever powerful dark energy is nearby. They split up into pairs to look for the Trix. However, this is a means of distracting the Trix so that Griffin can go to the heart of Cloud Tower and regain control of it.
The Trix attack Mirta and Lucy. Tecna modifies her ruby coin to show a hologram of Cloud Tower. As Stella and Musa debate what songs are better, the Trix trap them in a wall (after which they continue their debate). The Trix use the tower to capture some of the witches. Then they attack Bloom and Tecna, who transform and fight the Trix. The Trix gain the upper hand, until Griffin regains control of the tower and traps the Trix in a square of walls.
The Trix decide to destroy Cloud Tower by destroying its heart. The Winx fall into a crevice. The Trix notice there are four spires of Cloud Tower but only three stairwells, and figure the codex is inside the fourth spire. When they go over to it, they run into Discorda, the elder pixie of Cloud Tower. The Winx escape the void and confront the Trix, deciding to use Convergence on them. However, due to conflicting intentions of the Convergence - Musa wanting to destroy the Trix, Bloom wanting to capture them, and Tecna wanting to put a shield around the codex - the lack of harmony causes the Convergence to explode and send the Winx flying. Stormy knocks Discorda to the ground and Icy takes the codex from the spire. Their mission complete, the Trix fly away.
Griffin says Darkar will attack Alfea next, and will surely get the third codex if the Winx don't learn to fight together and trust one another.
- The Trix get the second codex for Darkar