Valtor decides to attack the star, Hypsos, in the constellation of the Hydra. When they discover that Hypsos is in danger, the Winx set off on a new mission, but Valtor uses his dark powers to turn the constellation of the Hydra into a threatening monster. While the Winx face the Hydra, Musa saves Riven and the two seem to be closer. Unfortunately, however, peace was cut short, because the two seems to distant away more!
- The Winx prepare a concert for the anniversary of the founding of Alfea.
- Noticing both Musa and Riven's constant disagreements, Flora and Helia decides to make Musa and Riven get back together.
- After learning that Hypsos is under attack, the Winx and the Specialists travels to Hypsos to stop them.
- Obscurum along with the Staryummies attack the Core of Hypsos.
- Thanks to his plan, Valtor transforms the constellation of the Hydra into a monster.
- Meanwhile, Obscurum continues to attack the Core of Hypsos.
- Thanks to Bloom's idea, the Winx manage to defeat the Hydra Monster thus returning it back into a constellation.
- Due to Twinkly's affections to Lumilla, she manages to break Valtor's spell and return Lumilla back to normal.
- During the concert celebration at Alfea, Riven plans a surprise for Musa but however, Musa got embarrassed and gets into a fight with Riven again.
- At the same time, Flora and Helia got into an argument when both of them defended them.
- Cosmix Power Supernova - Used by the Winx against the Hydra Monster.
- A storyboard of this episode was first released on October 15, 2018.
- This is the first episode in which the phrase "Magic Winx, Cosmix" is used when the Winx transform into Cosmix fairies.
- Helia giving love advice to Riven is a reference to Season 4 where he previously did the same thing in the aforementioned season.