The "promise" of the title refers to Lou's vow to Cagliostro: that he will never have to race again. This personal oath pits Lou against the horse's owner, Mallinckroth, who is determined to enter the weakened animal into high-stakes races regardless of the physical toll. Key Themes and Stylistic Choices
: The film critiques the commercial exploitation of horses in professional racing, highlighting the tension between a horse’s well-being and its status as a multi-million-euro asset.
The story follows sisters Lou and Emmie as they manage their family estate while their older sister, Charly, is away at art school. The peaceful setting is disrupted when a champion racehorse named Cagliostro is poisoned and hidden at Immenhof for protection.
