A weekend alone at home with the children - and already breaks out of the mess with Papa minor. For while Moll pushes overtime in the chocolate factory, between his children and the offspring of his boss a merciless battle breaks out: for cotton candy, homework - and the most famous circus dog in the world.

Grandmother Maria, Sam and the riding instructor Kaan are trying together to keep Gut Kaltenbach running, which is in financial difficulties. The ambitious Isabell supports her, although she secretly pursues her own goals. The impulsive Ari comes to riding training in Kaltenbach, where she develops a special relationship with Windstorm, the eponymous horse of the film series, and she also makes friends with Mika. Mika and Ari try to save the estate and protect Windstorm from reckless horse trainer Thordur Thorvaldson.

Due to the sudden outbreak of a hurricane, a traveling circus, famous for its stunning numbers with horses, calls into the small German estate of Kaltenbach. Soon, Ari realizes that one of the horses of this circus, named Orcan, is in mortal danger. Together with the boy Carlo and their faithful friend, the horse Ostwind, they try to save Orkan from the cruel owner of a traveling circus. However, the shrewd director unravels their audacious plan. And Ostwind's horse is also in trouble. Ari and Carlo have very little time to rectify the situation and save Ostwind.