Jack and Estefan's romantic wedding in Spain takes a detour when their flight is cancelled, forcing them to get married at the airport by their friend Miss Coco. McCoy's big job offer in London has Will worried about engaging in a long-distance relationship. While dealing with doubts about her current relationship, Grace meets a charming guy (guest star Reid Scott) at the airport who inspires her to make an impulsive decision. And advice from Smitty makes Karen reconsider her commitment to Nikki and her own sexual orientation.

The morning after his bachelor party, Jack realizes he's lost one of the thirteen gold coins he is to present to Estefan at their wedding so that their relationship will not be forever cursed. Although Grace denies it, Will becomes concerned that she is the only one compromising in her relationship with Noah. Karen makes it official when she shows up at Grace and Noah's dinner party with her new date, Nikki.

When both Will's and Grace's boyfriends, McCoy and Noah, ask them to move in, Will and Grace use each other as their excuse to get out of it. Meanwhile, a snowstorm keeps Karen at the office, where she meets Nikki, a woman who works upstairs. The storm also traps Jack in an elevator, causing him to reunite with an old flame, Drew, that tests Jack's commitment to a monogamous lifestyle.

After Grace's dad, Martin, is rushed to the hospital with a bleeding ulcer, Grace is shocked when he refuses to take Will's blood for a transfusion. When Will's mom, Marilyn, finds out, she uncharacteristically takes Martin to task. Karen's demands for Jack's wedding, along with upstaging him during his one-man show, cause Jack to uninvite Karen from his wedding.

Jack's insistence that Will be nicer to his fiancé, Estefan, backfires when Estefan thinks Will is in love with him. In a hurry to buy her boyfriend Noah a Valentine's Day gift, Grace unknowingly knocks over a prominent figure while going after a taxi. And when Karen discovers that Noah not only writes her favorite romance novels but also plans to kill off the main character, she forces him to rewrite the story.

Will gives local newscaster McCoy Whitman a second chance and, with the help of Jack, finally gets to know the man behind the newsman. Grace's campaign for Design Guild President hits a snag when the deciding vote comes down to her old nemesis, Val. Karen acts as Grace's campaign manager, and attempts to secure Val's vote by any means necessary.

Grace is enlisted by Malcolm to help him win back Karen's affections. Will's flirtation with his co-worker, Paul, takes a turn when details about Paul's home life put Will in an ethical dilemma. And Jack's run-in with Zusanna, the sister of his former acting teacher, reignites Jack's passion for performing.

When Will discovers Karen's estranged stepdaughter Olivia is a student in his law class, he attempts to solve their issues with a mock trial. Grace and Jack go on a diet together, but giving up their eating habits proves harder than anticipated.

Will and Grace's plan to win over Will's new boss goes awry when he drops dead in their apartment; Estefan and Karen's mutual dislike puts Jack in full damage control mode at his birthday dinner.

Will, Karen and Jack unknowingly take a hallucinogenic drug, which causes Will and Jack to wonder if they're each other's soul mate and has Karen giving her last "performance" as Mrs. Stanley Walker. Meanwhile, Grace is shocked when her high-powered client takes up with her sister Janet.

In order to land a handsome, gay TV news anchor (guest star Matt Bomer) with a pension for dim, frothy men, Jack convinces Will to not be himself and to act like someone silly and stupid—does he know anyone like that? Karen learns that her alimony will be severely limited unless she can get photos of her ex-husband's affair with Lorraine Finster, so she enlists Grace to go with her to the strip club where Lorraine works.

Will convinces Grace that her boyfriend, Noah, isn't in the wrong by refusing to let her meet his daughter, Katie. When Grace goes to apologize to Noah, she unintentionally meets Katie. Meanwhile, Will's mom, Marilyn, visits after the death of her beloved dog, and becomes upset when she doesn't get the emotional support she expects from her son. And Jack gets into an argument with his rec center boss, Theo.

When Will discovers Noah has a child, he promises to keep the secret from Grace; Karen and Jack's relationship is tested when she fires him from the play she's producing and replaces him with Jon Cryer.

While on a road trip with her father, Grace reveals a past secret, changing their relationship forever; legendary drag queen Miss Coco Peru emcees a lip-sync monologue throwdown to determine who will be Jack's best man, Will or Karen.

Now a certified psychic, Jack channels Rosario to help Karen open her heart to love again; Grace learns love means having to say you're sorry... to Will.

Will and Jack visit Jack's grandson, Skip, in Texas to watch him perform at his church's talent show. But when Jack learns Skip plans on singing "Diamonds Are A Girl's Best Friend," he becomes afraid for his grandson's safety. Karen tags along to check out the portion of the border wall she sponsored, only to discover that Beverley Leslie has claimed it as his own. Back home, Grace and Noah try to figure out if something is wrong in their relationship because their numerous attempts to have sex have failed.

Will, Grace, and Jack are upset when they discover they've been too preoccupied with the changes in their own lives: Will teaching law at Columbia, Grace running for president of the New York Interior Designers Society, and Jack's new relationship with Estefan to even notice Karen has not been seen in days – ever since her husband found out about her affair with Malcolm.

Grace's accidental run-in with Noah, a curmudgeonly man she follows on Twitter, hints at a possible new love interest. Jack wants to look younger before meeting Estefan's family on Skype but makes a terrible first impression after overdoing the numbing cream before his facial procedure. Meanwhile, Will helps Karen protect the intellectual property rights of her most prized possession.