A “restful” three-day escape to Briar Glen House curdles into scandal when a hunted young widow knocks at the wrong window after midnight, insisting that the man posing as her brother is controlling her money, her movements, and a missing letter that could ruin him; as secret meetings multiply around a blue cottage and a lake-side boat-house, a missing shoe, a dropped compact, and a third man on the path turn a romantic quarrel into a carefully staged disturbance where every guest is playing a part and the hotel’s sharp-eyed hostess refuses to let gossip write the verdict; inspired by historical crime of its era while remaining entirely fictional, The Blue Cottage Affair is an original Golden Age–style mystery about coercion, inheritance, and the dangerous ease with which a “helpful” man becomes a jailer.