Autumn has arrived at Castle Dark, and Nora Blake has settled into her role as an actor in Derek Corby's castle theatre troupe. She is troubled, however, by the setting of Derek's fall mystery: the catacombs in the depths of the castle. Yes, these catacombs are merely a set, the skeletons and cobwebs mere props, but Nora feels uneasy in the shadowy passages beneath Castle Dark. When a man is killed during one of their first shows, the eerie catacombs become a place of horror. Joined by her castle companions, Nora attempts to find the motive for killing a seemingly innocent victim.