17-year-old Simon’s sister Charlotte is missing. The lonely Fenland village the family recently moved to from London is odd, silent, and mysterious. Simon is epileptic and his seizures are increasing in severity, but when he discovers the local curse of the Naseby Horses, he is convinced it has something to do with Charlotte’s disappearance. Despite resistance from the villagers, the police, and his own family, Simon is determined to uncover the truth behind the curse, and rescue his sister.