Tritannus plans to activate the Emperor's Throne; the Winx must restore order when Tritannus takes the seal from the mystical Pillar of Light. The whole of Magix is plunged into darkness. Solaria is the most affected, especially by King Radius who gets sick because of his connection to the sun. The Winx Club go to the infinite ocean to restore the Pillar of Light, and Stella succeeds in doing so by tapping into her Sirenix abilities.