Continuing from the season finale in the year's first new episode, a dazed Grace is rescued by a handsome Jewish doctor who pulls her up on his horse and delivers her just in time for her insemination with an impatient Will. But their new relationship as expectant parents puts a strain on Will and Grace's relationship when they agree not to date until their baby is born. Meanwhile, a restless Karen can't make up her mind about cheating on her imprisoned husband with the genteel but ardent suitor Lionel.
After stalking actor Kevin Bacon, Jack lands his dream job when the unsuspecting celebrity hires him as his personal assistant and immediately assigns him to find out who's been harassing him. Elsewhere, while Will and Grace wait for the right color to appear on their home pregnancy test, Grace is visited by a handsome doctor who makes her a tempting offer. In addition, Karen looks for a way out of her on-again, off-again relationship with the courtly and irresistible suitor Lionel.
Grace is so entranced by her budding romantic relationship with a handsome doctor that she asks an impatient Will for an extra month to re-consider her commitment to conceiving their child through artificial insemination -- resulting in verbal sparring match.
While Will and Grace are feuding, Karen and Jack hatch a wobbly plan to patch up their differences about co-parenting a baby by tricking each one into attending the same child's birthday party. After arguing over who brought the better gift, the feathers continue to fly as the best friends fuss over their conflicting agendas.
On Halloween, Grace allows her new beau Leo to drag her into the rustic fall countryside for a long and scary bike ride -- along with a reluctant Will and his newfound friend -- but she finds that she can't pretend to be the outdoorsy type just to please her man. Meanwhile, Jack coaxes Karen into attending a gay men's therapy session when she feels slight -- very slight -- pangs of marital guilt over her earlier attraction to the courtly suitor Lionel.
Mr. Stein, the long-absent senior partner of Will's firm, shows up unexpectedly to reassume command and whip the troops into shape. When Will discovers he was recently released from the looney bin, Mr. Stein begins to rely a little too much on Will's eager assistance. Meanwhile, Grace and Jack are shocked to discover that their highfalutin' pal Karen is now poorer than a church mouse -- and living in her limo.
When Grace accompanies Leo to dinner with some 'friends,' she doesn't realize that he's tricked her and instead introduced her to his real parents -- and she soon regrets her earlier salty dialogue and suggestive attitude. Elsewhere, Jack is again confronted by Zandra -- his gruff acting teacher -- when he tries to showcase his meager talent in a class while a willing Will joins Karen in subjecting to a Botox facial injection.
After Grace impulsively accepts a marriage proposal from Leo, there seem to be a million roadblocks between her and an actual wedding, not the least of which is her best friend Will's unease about the whole idea. 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. Markus--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.
After a displaced Karen is booted from her Palace Hotel digs, a sympathetic Will agrees to let her move in with him -- at least until she turns his apartment into a federal disaster zone with her exorbitant lifestyle, forcing Will to try and unload her onto Grace's shoulders. Meanwhile, Jack loses style points when he poses incognito out of fear that the 'Gay Mafia' has it out for him.
On Christmas Eve, Grace is torn when she has only two tickets to 'The Nutcracker' musical and can't take both her best friend Will and new husband Leo -- but her back-and-forth indecision leaves Will spinning like a Hanukkah dreidel between a dithering Grace and his previous holiday plans with Jack and Karen.
When Jack convinces tangle-footed Will to join him on a gay soccer team, Will's inept play leaves him warming the bench -- which allows him to bond with teenaged Elliot who also is the last man called upon with his own youth soccer team. Meanwhile, Grace is delighted that Karen is giddy in anticipation of her date with a handsome restaurant owner.
When Karen sets Will up with her hot cousin Barry, Will finds a geeky guy with a scraggly beard and greasy hair? and he just came out. Meanwhile, Grace is puzzled over what to make of her strange bohemian neighbor when she moves into Leo's Brooklyn digs.
Will and Jack continue their campaign to adapt Karen's awkward cousin Barry to his new lifestyle -- but their flamboyant efforts to help him only remind Will of his own clumsy experiences when he came out in 1986. Elsewhere, Grace feels abandoned by Leo when he leaves for a month to offer his medical services to the needy in Africa.
Jack suffers Karen's wrath when he is seduced into friendship with her manipulative British romantic rival, who has set up house with Karen's ex-husband. Meanwhile, Will and Grace try to re-connect their lagging friendship with a competitive night of board games with their friends.
Grace has a girl's night in Brooklyn with Karen, Rosario, Ellen and new neighbor Julie -- and she offends Karen when she doesn't take her advice regarding Leo. Meanwhile, Jack reconnects with his childhood babysitter and falls back into childhood patterns, befuddling (and disturbing) Will.
Will and Jack's transformation of Karen's schlubby cousin Barry is complete -- but his coming-out at the HRC gala leaves Will with mixed emotions about his new 'creation,' prompting some unwanted advice from Grace. In another corner, Karen duels with her flamboyant rival Beverley Leslie in a war of wills during the silent auction.
A jealous Will keeps a wary eye on the re-modeled Barry when he spies him on a date with Jack, while Karen switches roles with Rosario pretends to be a maid in order to court a handsome maintenance worker. Meanwhile, Grace finds herself hanging out more and more in her old digs in Will's apartment as she waits for her husband to return from overseas.
Still nursing a grudge over his last failed relationship, Will forms a gin-soaked anti-romance club with other lovelorn losers -- his cuckoo boss, Mr. Stein, and Karen -- but the threesome shrinks dramatically when Stein takes a shine to the ever-ready Karen. Meanwhile, Jack sneaks a video camera into Grace's private boudoir and records her privates -- and posterior -- for posterity.
Will's attempt to orchestrate a surprise for Grace's birthday by sneaking Leo back from Africa deflates like so many birthday balloons when Leo arrives earlier than expected -- and after Grace bumps into Leo, they agree to an elaborate charade to keep Will's 'surprise' intact. Meanwhile, Grace recruits Jack and Karen to keep Leo out of the way until the appointed time but they take their mission too seriously.
Prompted by a sudden urge to meet 'real people,' Karen finds instant karma with a peculiar yet high-maintenance office worker who happily shares many of Karen's eccentricities -- including her taste in men. Meanwhile, when Will falls off his clogs and twists an ankle, he develops a habit of taking too many painhuggers, and his drastic personality change prompts a concerned Grace and Jack to intervene and interfere.
Will reluctantly opposes Karen when he represents her husband while she hires a goofy, immature young man who seems barely out of high school to argue her case -- and Will takes pity on the pseudo-slacker. Elsewhere, Grace hires Jack to temporarily replace Karen but finds she might have to choose between her friendship with him and a wealthy client who broke his heart.
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.
Karen, Will, Jack, and Grace go on a trip in Karen's yacht to sprinkle Stan's ashes into the Caribbean while Leo is flying to Guatamala with an atractive co-worker. While Karen sprinkles Stan's ashes she finds Lorraine has been stowing on board. While Karen and Loraiinne fight, Will and Jack get drunk. Lorainne pushes Karen off the board and Rosairo jumps off after her. The next morning Grace finds Leo's bag with a letter from his co-worker Danni saying that she wants Leo. Will wakes up in bed naked with a hangover and a naked Jack in the bed with him. Meanwhile Karen and Rosairo are stuck on a cargo boat.