In The Glamis Curse, the lives of Michael and Judy, two red squirrel twins struggling to grow up in the gray squirrel world of New York's Central Park, intersect with those of an orphaned Highlands lass, Lucinda, and her warlock knight protector, Sir Edgar, who have fled there from a deadly foe, the three immortal witches who beguiled Macbeth to murder his King and are sworn to preserve the curse upon all his descendents. Foraging for nuts late one night, the twins' father is trapped by one of the three pursuing witches. Sir Edgar frees the father but in so doing unwittingly reveals to the witches Lucinda's presence in the Park and ensnares the father and his family in a web of evil as the witches seek to carry out their blood oath. While Sir Edgar cannot convince Lucinda of the danger she faces, he is determined to protect her from it, and in the end he does, but only with the aid of the red squirrel twins and the gray squirrel nation that has closed ranks around them.