Bibi Blocksberg is a girl with special powers: she is a witch. She spends her summer holidays at riding school with her best friend Tina. The two girls go riding together every day. But this summer there are problems, such as the beautiful but unreliable Sophia, who is after Tina's boyfriend Alexander. She tries to get him to go with her to boarding school in England. Tina is completely overwrought. Worse, wily businessman Hans Kakmann is doing his utmost to extort a colt, Socrates, from Alexander's father. On the day of the great horse race at the castle, Bibi knows not what to do. Not only is Socrates at stake; so is her friendship with Tina.