After the Winx watch a movie that Flora says was creepy, Stella has a nightmare about her parents separating. The Nightmare Gargoyle, who is the cause of this nightmare, absorbs some of her power, turning lizardlike. In her nightmare, her reflection tells her she's a loser on the inside. When she tells the others, she says she could feel something clawing at her mind. The others suggest she is just freaked out by the movie, and they go back to sleep. Musa has a nightmare about her mother disappearing, then being unable to hear music, and Tecna has a nightmare about everything malfunctioning. Draining Musa's power, the Gargoyle turns insectoid, and draining Tecna's power turns bigger and lizardlike again. When Tecna wakes up she tells Musa that she feels drained of energy. This convinces Bloom that something is up. Mirta reaches out to the Winx from her pumpkin form, which Flora casts a spell to communicate with her, and she says that the Nightmare Gargoyle gives them nightmares and drains some of their magic at the most terrifying moment.
The next day, Bloom says that the Trix might be after her and know more about her past than she does. Stella suggests that the monster is after her, but doesn't sound too self-centered, saying the important thing is putting their heads together to defeat him. Flora is still trying to turn Mirta back and says for the first time that she hates the Trix.
That night, the Winx set a trap for the Nightmare Gargoyle, with Flora wrapping vines around him, but this only makes the Gargoyle bigger. The Winx transform to fight him, but Stella's attacks make him bigger and he sends her into another nightmare before they snap her out of it and chase after the Gargoyle. Mirta tells Flora that the Gargoyle is after Bloom, draining the others so it can get to her. When Bloom fights him he gives her a nightmare about being found in the fire before Stella snaps her out of it. The battle goes outside, and none of the Winx's attacks work on the Gargoyle.
The Trix appear and freeze Stella and Flora. Then they attack Bloom and feed her power to the gargoyle, who traps her with his tail. Then Faragonda appears and unfreezes Stella and Flora before she and Bloom use magic attacks on the Gargoyle and destroy him. Faragonda is furious at the Trix for their attacks on Alfea and goes after them, but they teleport away.
- The Nightmare Gargoyle is destroyed
- The Trix are expelled from Cloud Tower