Pendant que Jess fait la course pour préparer un mariage, Mick annonce un brusque changement de plan pour le club, et des tensions éclatent entre Bree et Martin.

Le premier jour d'école des filles fait remonter les souvenirs des O'Brien. Megan propose à Jess de l'aider à l'auberge. Rongé par la jalousie, Wes affronte Trace.

Trace part à Nashville pour y enregistrer son album. Abby enquête sur la relation distendue entre Mick et Thomas. Jess tente d'attirer un célèbre auteur à la librairie.

Trace prend une décision risquée, Bree et Kevin se lancent à la recherche d'une capsule temporelle familiale, et une nouvelle connaissance aide Abby à y voir plus clair.

Tandis qu'Abby, exténuée, s'apprête à affronter son père et Trace, Jess décide de faire un grand pas en avant dans sa vie personnelle.

Pendant qu'Abby et Trace s'offrent une escapade romantique loin de tout, Simon vole dans les plumes de Bree et Kevin découvre l'objet des tourments de Sarah.

Jess commet une erreur à la librairie, un différend éclate entre Trace et son groupe au sujet de leur avenir, la famille fête les 10 ans de Carrie.

Trace réfléchit à une offre qui pourrait avoir d'importantes répercussions sur sa carrière et sur sa vie avec Abby. Jess découvre enfin le secret de David.

With a nod to the past, Nell tries to save the Wish Fountain; Abby discovers a never-opened letter that she sent to Trace; Mick inherits a sailboat and reunites with his brother Thomas; and Bree welcomes an old friend back into her life. After Kevin witnesses a secret hug, Connor's future is thrown and Jess's future beckons with an invitation from everyone's favorite chef.

While Jess and Bree discover David's parents' secret plans, Abby joins Trace on tour, realizing that it will be impossible to stay clear of Trace's newfound fame. Thomas's vow renewal sparks Mick and Megan to re-examine their own relationship, as Connor reconciles with Kevin.

On the eve of the Chesapeake Shores Regatta, with Mick recruiting family members to join him on the water, Abby finally has to make a decision whether or not to break up with Trace for good. Meanwhile, Bree's relationship with Simon is rocked when Caroline appears, and David and Jess have to finally figure out their relationship without the B&B. In a surprise twist, a letter from Ireland might decide Nell's future.

As season four comes to a close, Trace and the O’Briens face decisions affecting their personal and professional lives. Trace weighs his relationship with Emma against her musical potential. Abby and Connor consider new career paths, while a new agent has Bree questioning what’s next.

O'Brien Construction's eccentric billionaire client, Evan Kincaid, comes to town and throws Abby and Mick off their game. At a moment of triumph, Connor discovers his law firm is hiding information from him, and Megan discovers a lost painting that leads her to a famous, reclusive local artist who wants nothing to do with her.

Jess and David host visitors in town for the traditional Snallygaster hunt. Mick and Thomas revisit a weekend-long hiking trip from their youth.

Sarah and Kevin come together with exciting news. Connor and Margaret’s law firm struggles to make ends meet, and when Mick’s pill addiction starts to noticeably affect his life, the O’Briens must rally together and stage an intervention.