On this episode of 'Glee,' Will Schuester (Matthew Morrison) and Finn (Cory Monteith) are in the midst of a feud after Finn admitted that he kissed Will's fiance Emma (Jayma Mays) -- which results in the cast members performing various mash-ups inspired by famous or well-documented feuds between musicians.

Artie (Kevin McHale) called a sit down between Finn and Will to deal with their recent problems. The group explores the recent tension via flashback with Will yelling at Finn for getting his coffee order wrong, demanding he re-clean the team uniforms and Finn finally reaching his breaking point and kicking over a music stand in anger. In response, Blaine (Darren Criss) assigns them a project to resolve their feud through song, so the group can be united and they can win Regionals.

Rachel (Lea Michele) leaves a doctor's office to tell Santana (Naya Rivera) that she is not pregnant. Rachel immediately wants to go back to her life as if nothing happened, but Santana reminds her there's Brody (Dean Geyer), also known as “donkey face” to consider.

Cut to Brody, who we learn has been earning his massive amounts of cash by being a male escort. Cue him singing 'How to Be a Heartbreaker' by Marina and the Diamonds as he reminds the older woman he is with that his fee is cash only.

Sue (Jane Lynch) is trying to convince Blaine to join the Cheerios, which he said he'd do when he thought the glee club had disbanded. She shows him a binding contract which she had his signature forged on and threatens him that if he doesn't join the cheerleading squad, he'll regret it.

In the library, Ryder (Blake Jenner) is flirting online with someone named Katie. During their conversation, he tells her about Unique (Alex Newell) yelling at him in the hall for going after Marley (Melissa Benoist) and causing a rift between Jake (Jacob Artist) and his girlfriend. The mysterious Katie recommends rectifying this through song.

Will is explaining to Finn why he's disappointed in him with his recent behavior, saying he gave him the glee club because he was lost and needed to get back on his feet, but Finn ended up betraying his trust.

Rachel is still trying to convince Santana that Brody is not a drug dealer, but a suspicious Santana trusts her intuition and steals Brody's pager while he is in the shower.

Blaine's life has become a living hell when Sue's minion Becky (Lauren Potter) gives him cement disguised as hair gel while Sue steals his identity to open 30 credit cards, takes out a house in his name and rents a plane carrying the message, “Blaine is on the Bottom.” Blaine invites Sue to solve their feud via song, and she recommends they compete as Nicki Minaj and Mariah Carey. If Blaine wins, she will rip up his contract.

Jake and Marley are having a tiff in the hall, with Jake angry at Marley for allowing Ryder to kiss her. They eventually make up, with Jake refusing to forgive his new nemesis and Marley refusing to give up their friendship. She promises Jake that no matter what, she only loves him.

In the choir room, Ryder and Unique perform 'The B—- Is Back’/‘Dress You Up’ by Elton John and Madonna. At the end of the song, Ryder admits that he's confused by Unique's cross-dressing. Unique reminds him that how she dresses is none of Ryder's concern, and Jake calls him out for even mentioning it.

Santana approaches Brody at NYADA, telling him he has to move out of the loft before launching into a rendition of Paula Abdul's 'Cold Hearted Snake.'

Meanwhile, Will and Finn are trying to work things out with a mash up of 'N Sync's 'Bye Bye Bye' and the Backstreet Boys' 'I Want It That Way.' Sam (Chord Overstreet) says he could feel the love during the performance and suggests the guys hug. Finn is all for it, but Will says that while he wants to, he still can't.

Santana returns home with the good news that she got a job at Coyote Ugly, but Rachel and Kurt (Chris Colfer) are waiting to tell her what she did to Brody was uncalled for. They give her the option to either move out or lay off Brody. She sticks to her guns and says she'll leave (to go live with Lena Dunham).

Ryder talks to Katie about his confusion with Unique, saying he doesn't understand how he can call himself a woman when he is obviously a man. Katie tells Ryder that Unique believes he's a woman and that's all that matters.

In the glee room, Blaine performs Mariah Carey's 'I Still Believe' and Sue (dressed like Nicki Minaj) performs 'Super Bass,' complete with Cheerios back up dancers and black light assistance. Her performance wins over the club and everyone but Tina (Jenna Ushkowitz) votes for Sue.

Marley catches Finn packing up to leave McKinley. She gives him a card thanking him for all his help and suggests that he “grow a pair” and stop letting Will “define” who he is as a person. Finn admits that the glee club and the school are what defines him since it's all he has and wants. She suggests he stay and when he says he would need a teaching degree to do that, Marley tells him to go get one.

Ryder calls a truce, apologizing to Marley for kissing her and admitting to Jake that he made a mistake. Jake says it might take a while to forgive him, but he'll work on it. Jake also apologizes to Unique and she tells them that she wore her girl's clothing on the way home and was chased by some girls and called a freak. Everyone, including Kitty (Becca Tobin) promises to walk Unique home and work together to win Regionals. After all, they will be the leaders of the club when everyone else graduates.

In Sue's office, Blaine is in his Cheerios uniform being told that he has been named the team co-captain. After being berated by Sue, Blaine walks into the hall and breaks into a smile. He is approached by Sam and admits that everything is going according to plan, that he is now in place to spy on the Cheerios and end Sue's “reign of terror.”

Brody enters a dark hotel room to meet his newest client. When he turns the lights on, Santana turns to him and smiles. Brody begs her not to tell Rachel, but she tells him he owes someone else an explanation as Finn walks out of the bathroom. Finn orders Brody to leave Rachel's life forever when Brody admits he loves her. Finn doesn't take this well and they end up in a violent altercation with Finn screaming, “Stay away from my future wife!” After breaking some lamps, Finn storms out of the room.

The New Directions, who have resolved all their problems, happily perform 'Closer' by Tegan and Sara.

Back in the library, Ryder tells Katie everything worked out. He admits to her that he's started to move on from Marley. When he asks Katie if they can meet, she suddenly goes offline.