Gert O'Connell and her amateur sleuthing friends, Judith and Henry Geeth, find themselves once again in the middle of a baffling murder case, this time at a sinister ancient Irish castle during the ghoulish season of Samhain. It is Hallowe'en night in 1953, and the eccentric owner of the Castle Bronmore, Colin Keeley, is throwing a costume party for some friends and relatives, but all is not fun and games. It soon becomes clear that Colin has plans to indulge a longstanding grudge against some of the party guests in a most macabre fashion - plans that include the skeleton of an old Irish patriot in the dungeon who has an unsettling tendency to spring to life and speak truths that some may not wish to be revealed. As tempers flare and political ideologies clash, the party quickly disintegrates into chaos, culminating in a gruesome murder. Now Gert and her friends, themselves considered suspects by the police, set about disentangling the clues to find the killer and, in the process, discover the truth behind the mysterious talking skeleton of Castle Bronmore.