With Christmas just around the corner and the discovery of the Renaissance diamond still fresh in their minds, Robert, Annie, Anton and Ellie discover that things around Darvil Manor have been mysteriously disappearing.
After tracing the culprit to a travelling circus, which set up nearby Devil's Leap, the children investigate, but is there more to the story than initially appears? And what do the mischievous clowns, Hubble and Bubble, have to do with this mystery?
