Grace blames her relationship with Will as the reason for her lack of interest in dating and decides they can no longer have fun together. Meanwhile, Jack enlists Will's help when the IRS catches up with him.

Will and Grace become hooked on a real-life soap opera unfolding in their neighbors' apartment when they begin eavesdropping through the new heating vent in their floor. As Will and Grace live vicariously through the marital infidelities of the downstairs couple, Jack feels neglected and enlists Karen's help in staging a play that drives the message home to his two best friends.

A successful and arrogant New York publicist hires Grace to decorate his house with the condition that she fixes him up with Will. But there's a problem: Will can't stand the guy. Meanwhile, Jack uses Karen to teach Will how to kiss someone he finds unattractive.

When Rob and Ellen admit that they don't have fun playing games with Will and Grace because of Grace's competitive nature, Grace works to change her image. However, as Grace loses her competitive edge, Will's emerges and he convinces his partner to care only about winning. Meanwhile, after learning how to administer CPR from Jack, Karen saves a workman's life.

A deceiving, but flattering, newspaper photo makes Grace look more ""endowed"" than she really is and gains her the attention of a former high school heartthrob who was never one to keep abreast of her before. Jack is destroyed to learn that Will had a fling with Walter, Jack's ex-boyfriend.

Grace is excited to meet Will's best friend from high school until she learns that the woman has made a request: to be implanted with Will's sperm. Now Grace has to confront Will about Will being her ""backup.""

Despite their history, Grace spends a fun evening with Val [ from ep. # 18 Grace, Replaced] only to have Will suspect her of stealing. Meanwhile Jack becomes attracted to the leader of Welcome Home-an organization for gays who have converted to going straight, so he acts straight to woo the man.

Just as Grace seems to be on the verge of a promising relationship, she undergoes a minor medical procedure that leaves her with an embarrassing ugly sore on her lip, but even though her new beau accepts her temporary blight, she cannot return the favor when she is horrified to learn he has six toes on one foot. Meanwhile, Will vies with Jack for the attentions of the same man until each agrees to walk away to preserve their friendship.

When Grace frets that she and Will might drift apart like their similar friends, she impulsively buys an expensive piano which she hopes will cement their mutual bond and love for music – or at least give her an excuse to perform a lot of show tunes. Meanwhile, when Jack is dumped by his latest romantic interest, he vents his grief by writing trashy novels which instantly draw Karen's passionate attention.

While a baleful Grace wallows in bed as she grieves over losing her boyfriend Nathan, an enterprising Will tries all his old tricks to spring her from her mattress and back into the real world's whirl. But when Jack and Karen arrive, Will fears that their bizarre efforts to help might actually drive Grace futher into her shell -- not to mention therapy.

Will and Grace feel they need more elbow room, so they search for larger digs and find an exquisite place—despite the efforts of Sandra Bernhard—but to finance the move, they illegally sub-let their old apartment. Meanwhile, a well-intentioned Jack begins filming a documentary of Karen's colorful life to celebrate her birthday but accidentally stumbles upon her estranged, lowlife mom.

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.

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.

When Grace and Leo join Karen for a friendly game of tennis at her exclusive club, her fierce playing style sends Grace fleeing the court. However, when the reason for her angry play is her hatred for Leo, Grace is determined to find a way for them to get along. Elsewhere, a nervous Will suckers Jack into visiting his depressed mother in Connecticut hoping they can cheer her up.

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.