During the day, Professor Cello is a popular teacher at the university. He loves riding across the countryside with his horse Kevin. However, when he meets the dwarfs Zwieback and Munkel, Professor Cello suddenly transforms into Acello at night, tasked with a mission for the Queen of Light: he must free the Earth from the swamp monster that is causing it to grow darker. With his new magical abilities, Acello faces many exciting challenges each night on the back of his winged horse and encounters a mysterious hermit, the spirit Hajo, crane Jako, and the little bear Edward, who support him on his mission. He visits the pyramids, the Golden City, and the Tree of Lights. But what role does the mysterious wooden chest play in all of this? Where is the red jasper stone that everyone is after? And will Acello...