Summer with the ghosts

Ten-year-old Caroline travels from her home in Montréal to Austria to visit her filmmaker father, who is on location in a medieval castle. Something seems to be going wrong with the special effects being produced by the long-time effects director, Otto. Catherine suspects that someone is sabotaging the production, and decides to investigate. With the help of Jakob, an Austrian boy who is the same age as Catherine -- and who has been keenly following the activities of the film crew -- Catherine uncovers the culprits: the ghosts of five nuns who were buried alive some 500 years earlier for daring to dance during the night...