Monica's credit card has been stolen & she is freaking out at all the charges being rung up.
Phoebe, grossed out, tells Ross to get control of Marcel who is humping a lamp behind the sofa. Ross orders Marcel to stop; Marcel runs into Rachel's room. Monica tells Ross to fix the humping problem but Ross thinks it's just a phase.
Late at night, Monica is still looking through her credit card bill as Rachel emerges from her room. Monica is bothered by the fact that the woman pretending to be her is "living my life & she's doing it better than me."
Joey & Chandler discuss stage names at Central Perk. Joey's agent wants to change his last name of Tribbiani to something less "ethnic". Joey also wants to change his first name to Joe, to sound more grown up.
Chandler plays with Joey and suggests the name of Joseph Stalin. Joey likes it, not having a clue about the origins.
Monica is on the phone, learning the fake Monica signed up for tap She wants to meet the woman who stole her identity. Rachel & Phoebe worry that Monica has gone over the edge.
All 3 girls arrive at the Tap They sit down and look at the various women, wondering who the fake Monica could be when the teacher comes up to them and makes them put tap shoes on and participate.
The music starts, everyone dances in unison. Monica can't find the beat nor the step. Phoebe is dancing Phoebe-and Rachel is in perfect sync with the rest of the telling Monica, "Just click when they click."
The teacher orders everyone to partner up. Phoebe takes Rachel, leaving Monica the odd one out. The teacher invites Monica to be her partner, at the front of the oom, adding to Monica's anxiety.
Monica slowly walks toward the front of the room until the teacher grabs her hand and pulls her forward. A woman suddenly bursts in, apologising for being late. The woman asks the teacher who the "new tense girl" is, and the teacher pairs Monica off with her, the fake Monica. Monica is stunned when the woman introduces herself, so she calls herself Monana.
Ross enters Central Perk, mortified. The vet told him that Marcel has reached his sexual maturity and the more time goes by, the more aggressive and even violent he will become. Marcel needs to be placed in a zoo.
The 3 girls enter; Phoebe tells the guys the good news: they found the fake Monica. They took her to lunch after dance The guys can't believe their cavalier attitude but Monica found her to be an "astounding person" with an "amazing spirit."
At Monica & Rachel's; Monica & Fake Monica are telling Rachel about their day together. The two got thrown out of a hotel for pretending to be someone they weren't. Rachel, excited for Monica, leaves for work.
Fake Monica tells Monica that they are going to audition for the Broadway show Cats tomorrow, to the horror of Monica who can't dance at all. Fake Monica tells Monica she used to be like her until she saw the movie "Dead Poet's Society." She said the movie was so boring that she realised she would never get back the two hours she spent watching it. And that scared her into living out her fears.
Time passes. Ross is at Monica's, reading rejection letters from various zoos. Joey enters, upset that Chandler knew there was someone by the name of Joseph Stalin.
At Central Perk, Ross is talking to Dr. Baldhara, zookeeper. The doctor asks Ross if Marcel fights with other animals.
Ross says no. The doctor asks if Marcel can handle small objects like a hammer or small blade. Ross is horrified.
Chandler & Joey excitedly burst in with Marcel. They tell Ross that Marcel got into Ross' dream zoo: San Diego. Ross is ecstatic.
Rachel is dusting the apartment. Monica bursts in, very drunk. Rachel is upset. Monica goes over to the faucet, drinks from the tap, saying "water rules!"
Rachel tells Monica her job called and wonders if she will show up for work.
When Monica announces she is going to the "Big Apple Circus" instead, Rachel is completely disturbed that Monica couldn't care less about losing her job. She tells her, "This is not you." and Monica responds by saying, "I am so much more than that, I'm Monana!"
Rachel answers the phone. It's for Monica; it's the credit card company. They arrested the fake Monica.
Monica is at NYC Dept of Correction to visit the Fake Monica. Monica finally tells the fake Monica the truth, she is not "Monana" she is the real Monica Geller. The fake Monica is stunned. But Monica thanks her for giving her a new outlook on life.
Monica stands by the door of the Tap for a moment before deciding to join. She still dances lousy, but she is having fun.
At the Airport, everyone but Monica is there to send off Marcel. Each gives Marcel their own good-bye. Rachel brings Marcel a teddy bear, knowing it will probably become his humping buddy in the airplane.
Ross takes a moment away from the group to talk to Marcel alone. He sits down as Marcel sits beside him. He tells Marcel he will always miss him and never will forget about him either. As his sappy speech continues, Marcel climbs down & begins humping Ross' leg. Marcel is put in a cage & taken away.