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.

Chaos reigns with the closure of the Bridge, and the O'Briens are at war over Bree's manuscript. Meanwhile, Kevin is heartbroken visiting Sarah's family in Philadelphia, especially after he's offered his dream job back in Chesapeake Shores. When Trace realizes that he might not return to Chesapeake Shores, his relationship with Abby is cast into doubt, as Jess wonders if her relationship with David can survive without the B&B.

Battle lines form after Megan reads Bree's manuscript; Trace and Mick disagree over the future of the Bridge; with Jess's B&B's being devoured from within, it appears that the same might be true with the O'Brien family.

Trace discovers that the general manager of The Bridge stole large sums of money, pitting Trace and Mick against one another. At the same time, Abby realizes that she can't be a perfect boss, parent and girlfriend, and David Peck's sister arrives, threatening Jess and David's relationship. Meanwhile, Connor rediscovers Danielle, and Kevin accepts that he might lose Sarah.

Boyfriend and girlfriend problems abound: While Wes's new practically perfect girlfriend reminds Abby that she might be the only "mom" in Carrie and Caitlyn's life; David and Simon's presence in Chesapeake Shores puts Jess and Bree in an unusual position; and Mick and Megan finally come to terms with the direction of their relationship. Meanwhile, Nell enlists Connor's help when she discovers that her rival in a flower show is cheating.

With Trace still on the road, Abby and Trace find a way to combat the loneliness; with Simon in town, Bree has to define a new normal; Sarah is injured on the job.

Jess and Bree discover David's parents' secret plans; Abby joins Trace on tour; Thomas's vow renewal sparks Mick and Megan to re-examine their own relationship; Connor reconciles with Kevin.

Trace's role in Abby's family is questioned; everyone helps out running the B&B; Connor learns the truth about Danielle.

After Trace's dad cleans out the attic at home, Trace and Abby goes through his old things. While doing so, Abby finds an old unopened letter she wrote years ago. Mick begins working on refinishing an old boat. Conner and Kevin's relationship gets strained when Kevin discovers Danielle in a lie. Bree asks Abby to read her manuscript, hoping to prove a point that it isn't about Jess. Bree gets an opportunity to produce a play in Baltimore, where she runs into her old flame, Simon. Thomas and his wife Robin arrive in town, much to the displeasure of Nell, who is working to save the town's beloved fountain.

After months away on tour, Trace returns to Abby. Trace's Chesapeake Shores homecoming becomes complicated, however, when his growing fame draws unwanted media attention to his relationship with Abby and her girls. Mick faces off against Connor in an environmental legal battle. Though the two are on opposing sides, Mick tries to warn his son about a major error before it is too late. Jess discovers Bree's manuscript and is shocked to discover what's inside. Meanwhile, Kevin continues his paramedic training, and grows closer with Sarah. When Trace and the O'Brien family come together for the annual oyster festival, Nell recruits the family to save a beloved landmark.