Now empty-nesters, Cassie and Sam celebrate their first wedding anniversary. Abigail and Donovan's relationship continues to be challenged by their families' curse. Cassie's Grey House guest has intentions for visiting Middleton that are different than she claim.

Cassie judges Middleton's chili cook-off, which brings out fierce competition among residents, including Sam. Martha receives unexpected competition in her once-uncontested run for re-election. Cassie unearths a time capsule that reveals information about her current Grey House guest's background.

Cassie, Abigail and Joy browse an estate sale, where Joy hopes to find a clock for Martha's renovation. Stephanie's ex-husband, Wes, comes to town to pack up their shared cabin.

Martha fills in as the local Dear Debbie advice columnist, getting an anonymous letter that adds intrigue to a progressive dinner attended by all of the Middleton couples.

Cassie pursues a temporary art history professorship while Sam diagnoses Adam. Abigail and Donovan realize that the missing diamond from the Middleton treasure may help break the curse.

Cassie teaches her art history students a lesson on perspective that transcends the classroom. Sam performs surgery on Adam, who worries about his recovery. Joy has an upsetting dream about Abigail and Donovan's relationship but it may not be what it seems. Martha tries to win over a French delegation and secure Middleton's status as its sister city.

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.

During a chocolate festival at Grey House, Cassie hosts Kenny "the chocolate king", whose big persona hides his insecurities about taking over the family business from his father. Sam butts heads with the new hospital administrator when he goes around him to hire a new surgeon. Abigail gets a surprise proposal from an old college friend who makes an unexpected visit. Joy's former business partner arrives at Grey House to formally dissolve their partnership. Inspired by an answer at a local trivia night, Sam and Donovan uncover a new clue surrounding the Merriwick-Davenport curse.

Cassie and Sam's plans to steal away to Chicago for the weekend go awry when he has to stay behind for work. Instead, Cassie takes her book club friends so they can all recharge. Joy questions her decision to partner with Donna again as they work on Martha's renovation. Abigail bristles at Donna's style but their may be another reason she hasn't taken to her. Abigail and Joy join Cassie at the memorial luncheon for her mentor Olympia and make a surprising discovery that could bring them closer to breaking the Merriwick-Davenport curse.

Cassie is sad that her temporary teaching assignment is winding down. Sam is forced to take unused vacation time, so he and Cassie try to find a hobby they both enjoy. Joy has a decision to make when Donna finds a new job for them in Vermont. Martha's worried about her housewarming party when final details of the renovation go awry. As Adam's mission nears, he and Stephanie try to figure out what this means for their relationship. Abigail and Donovan reunite to make one last stand against the curse and fight for their future.