When his work for Harlin takes up all his time, Will drops all his other legal clients; a decision that later comes up to bite. Meanwhile Grace tries to teach Karen how to live on a budget.

Will thinks that he has another chance with Michael, his old boyfriend and Grace's new client. Meanwhile, Karen tries taking her ""career"" more seriously and asks Grace for greater responsibilities.

Forced by his boss to betray both of his friends, Will quits--only to discover that everything isn't as it seems. Frustrated, he leaves a lost Jack and Grace behind and ends up on a tropical island without a care in the world. Until Ben shows up.

In a flashback to Thanksgiving 1985, coed Grace invites her college boyfriend Will home to meet her family, but their romantic relationship swerves dramatically when a conflicted Will phones a teenaged Jack for some crucial advice. Unfortunately, Will and an angry Grace end up temporarily estranged when he blurts out the truth and she orders him out of the house -- and her life.

In a flashback to Thanksgiving 1985, coed Grace invites her college boyfriend Will home to meet her family, but their romantic relationship swerves dramatically when a conflicted Will phones a teenaged Jack for some crucial advice. Unfortunately, Will and an angry Grace end up temporarily estranged when he blurts out the truth and she orders him out of the house -- and her life.

Grace gives romantic advice to her slovenly new neighbor, Nathan, in hope of reuniting him with his girlfriend so he will move away. Meanwhile, Will and Jack are out on the town with an unwelcome chaperone: Karen's oblivious mother-in-law.

During an intimate moment, Nathan pops the question of marriage to Grace but she recoils simply because the situation didn't fit her childhood fantasy of a proposal. When she realizes her mistake, she returns the favor, but doesn't get the response she hoped she'd get.

After Will and Grace decide to have a baby together, obstacles pile up before them, including a missing specimen sample and bungled insemination efforts that have them teetering between artificial and natural means—all leading to mis-conceptions. Meanwhile, Jack considers giving up his show-business aspirations, until he gets some career advice from a ""divine"" entity: his idol Cher. Likewise, married Karen is sorely tempted by the romantic tickling of a rich and natty gentleman.

Grace and Leo impetuously take their vows at a Central Park wedding that is a ratings stunt hosted by Today's Katie Couric. Grace's pals, especially Will, are hurt that they weren't invited, but all seems forgiven when everyone including Grace's outspoken mom and the subdued Mrs. Marcus gather days later for a swank reception. It should be a festive bash, but the emergence of unsettling details about Leo and about the park nuptials give Grace reason to wonder whether she has made a mistake.

Grace's wedding to Leo leaves Will feeling upset over losing his best friend.

In the middle of her divorce proceedings, Karen learns that ex-husband Stan has suddenly passed away, and the funeral becomes a contest of wills between Karen and her British rival, and a free-for-all when the will is read for everyone who ever felt deserving, such as Will. Meanwhile, Grace is shocked when recently returned husband Leo is called back into service by Doctors Without Borders and asks her to make the trip with him to Guatemala.

When Grace's rebellious, free-loading older sister Janet comes to town to launch her new jewelry enterprise/folding table subway stand, Grace decides to put her foot down casting her sibling away. However, when her tough love prompts Janet to go corporate by taking a 9-5 job and studio apartment, Grace can't seem to handle her new image. Meanwhile, Karen continues to spurn Lyle's proposals of marriage, only to have a change of heart after Lorraine stops by for an impromptu visit, to declare her disapproval over Karen's ""relationship"" with her father.

Opting to forgo a picturesque fall wedding to elope in Las Vegas, Karen hops a plane to ""Sin City"" with fiance Lyle and faithful friends Will and Jack but when she bumps into vacationing superstar Jennifer Lopez, she asks J-Lo to sing at the ceremony. Meanwhile, Leo returns from Cambodia to meet up with Grace at the wedding, but their reunion is delayed by a freak design accident.