For a potion test, Flora has to find a rare and special flower that only grows in the Black-Mud Swamp. The Winx venture into the swamp together, where they meet some water fairies, victims of a spell cast by a red willow. The willow is capable of putting anyone who approaches it into a deep and long sleep. The five fairies battle a monstrous creature and the terrifying red willow. After a spectacular display of power, the fairies manage to get the flowers they need and defeat the red willow. 

Bloom returns to Gardenia to visit her parents. She shows off her newly acquired power: she can "feel" the nature and intentions of people, understanding whether their intentions are good or bad. Mike and Vanessa decide to finally tell her the truth - she is actually an adopted child! Mike, her 'father', found her in a fire during one of his firefighting missions. Bloom is completely shocked by this news.