Petronella has washed a magical sock for her grandmother. But when she wants to take it down from the line the next day, she discovers: Oh dear, oh no, the sock is gone! Immediately, the apple witch sets off in search of it. But no matter where she flies, whether to the apple orchard, to Wimmerding, or to Haspelwald - the precious item is nowhere to be found. Could the raven witch Hexobine be the thief? In the large, dark witch tower, there are many rooms to rummage through. Finally, in the basement, Petronella is in for a big surprise...