"Portrait painter Iris Grey arrives at Pitfeldy Castle in the Scottish Highlands, at the request of Baron Jock MacKinnon. Jock has commissioned Iris to paint a portrait of his fiancé, an American socialite Kathy Miller, ahead of their New Year wedding. Kathy invites Iris into her confidence, as she's received a series of threatening notes asking her to call off the wedding. Iris begins to investigate, and when a body is discovered in the grounds...