Gillian (Kim Novak) is a fiercely independent young woman living in Manhattan’s Greenwich Village and running a shop selling African art and artefacts. After taking a liking to her neighbour Shep (James Stewart), and then subsequently discovering that he is engaged to her old school nemesis Merle (Janice Rule), Gillian decides to break them up by bewitching him on Christmas Eve with a spell to make him fall for her instead.

Supported by her eccentric Aunt Queenie (Elsa Lanchester) and her bongo-playing warlock brother Nicky (Jack Lemmon), Gillian must decide whether to stay with her community of witches and warlocks or give up her powers to be with Shep.