In their new mission, the Winx have to find the last fairy on Earth, so bringing people back to believe in magic and fairies. Thay start to live on Earth and search for a way to do that. When people will believe in them, the Winx will get the Believix power: thanks to this, they will find Roxy and will save her from the wicked Fairy Hunters, whose goal is trapping all the Earth fairies.
