Museum curator Virginia Davies is on a vacation with her fianc , Dr. Andy Clark, and his parents to Scotland to visit Andy's Great Uncle, The Baron of Finlaystoke. They are there to witness a centuries old ceremony involving a locked chest and a mysterious historic treasure. Murder, however, is not on the agenda. Snobbish relatives, pompous lawyers, poisonings, a madman on a motorcycle and someone out to kill her make for an interesting party and another misadventure for Virginia.
With the police and killer trailing behind, Virginia hunts for the mysterious treasure and murderer at the Baron's ancient stone manor. Virginia figures out what the treasure is, but locating it proves daunting until she remembers the clue from the chest. Weaving her way through secret tunnels, and a using a cache of medieval weapons she discovers, Virginia turns the tables on the culprits in the cutting conclusion.