After spending the night with Helen, Joe thinks they're a couple again. But, Helen has other thoughts about their night together and goes to New York to see Davis anyway.

Helen's sister Casey arrives and spoils Joe's dinner plans with Helen.

After Brian's depression over Alex's departure results in a near break-down during a flight, Joe suggests he go see a psychiatrist but winds up treating Joe instead. Meanwhile, Lowell is in search of his favorite hat that Antonio carelessly lost.

After his therapist pronounces him fully recovered from his break-up with Alex, Brian plunges back into the dating world and Antonio insists he go along. Meanwhile, Lowell prepares a commencement address for his Alma Mater and Casey has trouble getting a good haircut.

Lowell invests a financial windfall in an old wax museum that he renovates and re-opens.

Brian and Casey decide to throw Joe and Helen with a surprise engagement party as a way to apologize for not giving them some much needed time alone.

Antonio becomes the personal chauffeur to a wealthy businessman visiting the island in order to pay off an IRS fine. Meanwhile, Joe is irked that Brian had an erotic dream about Helen.

Joe, Brian, Helen, and Lowell struggle with the return of their 9th grade English teacher on whom the boys had a serious crush. Meanwhile, Roy is dubious about why a "Simon Says" expert wants to marry his mother.

Helen and Casey's mother arrives on Nantucket to help plan and fund the wedding. Meanwhile, Fay and Roy split a ticket to a Barbara Streisand concert.

To counteract Roy's Aeromass promotions, the Hacketts' woo a famous astronaut as a spokesman for Sandpiper.

The airport's Air Traffic Controller snaps when he learns that Helen sold her last jelly donut to Antonio.

When Sandy Cooper returns to the island, Joe fears yet another bizarre encounter with her. Meanwhile, Fay forces Antonio to wear the clothes of one of her dead husbands that she can't bear to part with.

With nothing to do one Saturday night, Joe and Helen start socializing with a new couple on the island. Meanwhile, Brian and Casey start hitting the singles hangouts together and Antonio becomes Lowell's "hands" when Lowell injures his working on the cab.

Roy flies in a mail-order bride from Russia. Meanwhile, Fay convinces Lowell to pretend to be her lover to impress her visiting friends.

Struggling to agree on wedding plans, Joe and Helen decide to crash another couple's wedding to check out a place. Meanwhile, Lowell and Antonio train for a Polar Bears competition.

It's the gang's High School reunion. Brian dates one of his sweethearts who has a child that is the spitting image of Joe. Helen grapples with the mean girls who tormented her. Not to be left out, Antonio poses as an exchange student who briefly went to the school and Lowell discovers his shop teacher isn't all there.

Joe finds out some very important news that he's been waiting for about Brian's girlfriend's son. Lowell rethinks his profession and Antonio tries to work up the courage to finally tell Casey his true feelings.

At the beckoning of Helen, Joe reluctantly hires Casey to replace Fay, who has retired, at the ticket counter proving to be a model of efficiency and professionalism.

Brian's excitement over appearing on a popular Boston talk show is dampened when his ex-girlfriend Alex also appears.

Casey is enamored with a sculpture that Lowell made out of old plane parts and convinces him to make more for a prestigious art gallery. Brian finishes a roll of film not knowing that it will soon go to her parents.

Brian makes a video diary of Joe and Helen's relationship for them as a wedding gift.

The gang sees opportunities to benefit from Carlton Blanchard's impending death as his nephew invites them to Carlton's house to start selling off the old man's items.

Helen is in desperate need of Roy's help when she discovers that she and Antonio are still married.

Antonio's workaholic cousin and his wife arrive for a visit and Antonio struggles to suppress his feelings for her as she confides in him about her marriage. Meanwhile, Helen's side of the family outshines Joe's as the wedding gifts start to arrive.

Brian and Casey throw their siblings the requisite bachelor and bachelorette parties. Joe's party is a dud while Helen's is a hit.

Joe and Helen's wedding day gets off to a rocky start leaving the gang to overcome insurmountable odds to get the couple married.