Cassie and Sam bring Grace and Nick for an overnight at the lake house, hoping time together will help the kids resolve their differences and help the soon-to-be family bond, but Cassie faces a few obstacles before they start acting like a family again.
A mysterious, darkly beautiful woman named Cassandra Nightingale moves into an old, abandoned house which is reputed to be haunted by its original owner, "The Grey Lady". The small community is divided in their opinion of her: Some want her to stay (especially widowed police chief Jake Russell and his two children), while others want her to leave. Through the course of the story, seemingly magical things happen, and the community attributes these occurrences to her. Everyone begins to wonder if she is really a witch.