On the eve of her wedding, Cassie's long-lost foster brother Vincent makes an unexpected appearance, stirring up conflicting feelings; Sam searches for the location of the fabled Forever Tree as a gift for his soon-to-be wife.
With the wedding only a day away, Grace realizes how much she misses her father; Cassie takes Grace on a journey down memory lane to understand that Jake will always be with them; the clock is running out on Sam's quest to find the Forever Tree.
Cassie and Sam celebrate their honeymoon at a country winery, where they help their hosts deal with a dilemma over the future of their family estate; Grace goes to great lengths to avoid dealing with the pain of heartbreak.
Cassie plays host to Henry, a dashing stranger, and Olivia, a visiting poet; the two quickly fall for each other., but a revelation about Henry's true identity could throw a wrench in their burgeoning relationship. Abigail and Donovan squabble.
Martha is reinstated as mayor of Middleton and pits Grace and Luke against each other; Grey House hosts two best friends, Paige and Chelsea -- both of whom are worried that Chelsea's upcoming wedding will cause them to drift apart.
Cassie, Grace and Abigail take a road trip to Cassie's alma mater, Wellingsly College; Cassie reconnects with an old friend, who's contemplating her future as a professor; Abigail takes advantage of the trip to evaluate her relationship with Donovan.
Martha and her husband, Tom, visit Grey House; Cassie and Sam realize that they still have some things to learn about one another; Donovan's overbearing mother complicates his and Abigail's relationship; Grace and Luke go on their first date.
Martha discovers the original Middleton town charter and learns that it holds clues to the location of a fabled treasure.
Middleton is buzzing with the arrival of a comet that appears once every hundred years; everyone in town gets a wish, but not all wishes will be granted.
Grace and Nick's graduation day arrives and Cassie tries her best to make the occasion truly magical.