As Cassie gets ready for Grey House's 225th birthday, Martha leads the group in a tableau vivant to recreate one of Nathaniel Merriwick's paintings. The exercise unexpectedly leads Abigail and Donovan to new clues as they continue their quest to find the key to breaking the Merriwick-Davenport curse. Meanwhile, Sam appeals to Adam's competitive side to encourage him to continue with post-op physical therapy. Joy experiences life differently when her intuition suddenly takes a holiday, while a social influencer staying at Grey House has technical difficulties forcing her to view life outside the confines of her phone's camera lens.
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.