When three schoolgirls and a teacher from Appleyard College disappear on Valentine's Day in 1900, the event has a far-reaching impact on the rest of the school, as well as the nearby township. People quickly come up with theories about the disappearances as paranoia sets in and long-held secrets surface. As authorities get further into their investigation, the mystery surrounding the case seemingly deepens. Natalie Dormer (`Game of Thrones') stars in this adaptation of Joan Lindsay's novel of the same name.