Up in her grandmother's attic, Annie Dawson finds an antique key that is the first clue in a 150-year-old mystery and an ill-fated Civil War love affair. As she and the ladies of the Hook and Needle Club try to make sense of the clues, they must also figure out how to help Mary Beth when she fears she will lose her beloved needlework shop. Perhaps the key to both problems is in Annie's hands.