(Y/n), Mordecai and Rigby are walking to the park's cave, chanting excitedly. "It's time for cave-party times, baby!" Mordecai said. "Aw yea-yuh! Let's get this camp fire going!" Rigby said. Later the trio are roasting marshmallows on the fire. "Dude, it's gonna burn. Dude seriously, it's gonna burn. You're gonna burn it." (Y/n) said. "STOP IT!!!" Rigby shouted. "You're burning it right now." (Y/n) said. The marshmallow catches on fire. "Aw, man!" Rigby said. "I told you." (Y/n) said. Due to the fire, a block of ice nearby starts to melt. Later, (Y/n), Mordecai and Rigby are partying, playing music, and drinking soda, while the block of ice continues to melt.
"Dudes, where do you see yourselves in 10 years?" Mordecai asked. "I don't know, what am I a psychic?" (Y/n) asked, and Rigby snickers. "Easy, I'm gonna be a stuntman." Rigby said. "Dude, that's so lame. You'll probably still be working at the park." Mordecai said. "STOP TALKING!!!!!!" Rigby shouted, and (Y/n) laughs. "I know I will. Besides, I don't have anything else to live for besides my friends here anyway." (Y/n) said. "Wait, what? But what about your family?" Rigby asked her curiously, and (Y/n) froze, then avoids eye contact. "Forget them. Besides, you guys are my family." (Y/n) said. Later the block of ice starts to melt and there's a man's head on top of the block of ice while (Y/n), Mordecai and Rigby are playing video games. "Hey, guys, ever think we should bring in another friend?" Rigby asked. "You mean, like a fourth person? I guess we keep our inner circle pretty small. But
it's not like we're ever gonna find anybody cool enough for the park, so..." Mordecai said. "Well I know SOMEONE (Y/n) might have in mind for a fourth friend." Rigby smirked, and she turns to him and raises an eyebrow. "Oh yeah, who?" She asked. "You know, the new employee. The llama or whatever." Rigby said, and (Y/n) scoffs. "Thomas is a goat, idiot." She said, and Mordecai snickers. "Same difference." Rigby said. "No Rigby, they're completely different animals." (Y/n) said.
Later the trio are in their sleeping bags. (Y/n) yawns. "Good cave party dudes." She said. They all fall asleep. The block of ice finally melts completely. A man opens his eyes and walks towards (Y/n), Mordecai and Rigby and a drip of water fell on (Y'/n)'s face that wakes her up and she looks up and screams.
"Rigby...Mordecai... wake up. Rigby! Mordecai! Guys, wake up!" (Y/n) shouted. The duo wake up and see the man and scream as well. "Dudes, just keep quiet!" (Y/n) said. The man then comes out of the dark and grunts. (Y/n), Mordecai and Rigby scream and come out of their sleeping bags. "STAY BACK!" Mordecai said as he and Rigby step in front of (Y/n) protectively. The man hits the radio and it turns on. He begins to dance. "Whoa! Dancing caveman!" The trio said. "This guy is awesome!" (Y/n) said. The caveman looks at the trio. "Dude, you're awesome!" Mordecai said, and the caveman gives a thumbs up to the trio. "Looks like it's time to go from "(Y/n), Mordecai and Rigby" to
"(Y/n), Mordecai, Rigby and Dancing Caveman". Mordecai said. "Fourth friend!" The trio said. "But we can also go to (Y/n), Mordecai, Rigby and Thomas if the caveman doesn't work out." Rigby teases, and (Y/n) smacks him on the head angrily. "Ow!" Later at the Snack Bar, the caveman is chugging cheese. "Chug! Chug! Chug! Chug! Chug! Chug! Chug! Chug! Whooooo!" The trio said.
The caveman yells in the same accurate manner. He tries to activate the machine but nothing happens. "Anyone who can chug that much cheese is cool in my book." Mordecai said, and (Y/n) giggles. The caveman grabs the machine and throws it out of the bar near two kids. They run off screaming. Benson arrives witnessing the scene and grunts. "Who is that?" Benson asked. "He's our new friend. Dancing Caveman." (Y/n) said. ""Caveman"? No. No. No way. I'm not having a caveman at the park. We aren't insured for it." Benson said.
"What? That's not fair!" (Y/n) said. "Yeah, we can't just get rid of him!" Rigby said. "A caveman cannot fit into this modern world." Benson said. "You don't know that!" (Y/n) said. The caveman squeezes a ketchup bottle and a mustard bottle into his mouth. He throws the bottles at Benson, who blocks them with the clipboard. Benson raises an eyebrow at (Y/n). "You were saying?" He asked sarcastically. "But he's one of us now." Mordecai said. "Really? What's his name?" Benson asked. "Uhhh...." Mordecai and Rigby said, and (Y/n) face palms. "Get rid of him!" Benson shouted. "But he'll die out there all alone. Come on, Benson!" (Y/n) said. "Pleeeeease?" The trio asked. "Ben...sooon?" The caveman asked. "Fine. You have a week to get him civilized." Benson said.
"Nice!" The trio said. "Thanks, Benson." Mordecai said. "But if he isn't up to park standards in a week, I'm calling the pound!" He walks off. "We're gonna need some help." (Y/n) said. Later at Pops' house, (Y/n), Mordecai, Rigby, Muscle Man, Fives, Skips and Pops get the caveman to be civilized. They bring a chalkboard to the kitchen. He is taught Lauguage, Technology, Health & Hygiene, Laws, Music, and a bunch of other aspects of lifestyle. Thomas even decided to help (Y/n) teach him a few extra things. Later, while everyone is talking, the caveman comes down the stairs, revealed to be in clothing.
"That is the most civilized caveman I have ever seen." Skips said. The caveman laughs. "Please, call me Gregg." The gang are impressed as they walk to him. "Good luck with the Benson test, my good man." Pops said. Everyone but (Y/n), Mordecai and Rigby leave. "Dude, this is perfect! Benson will totally let you stay." (Y/n) said. "Pfft, yeah! He'll probably offer you a job." Rigby said. "Alright, let's go." Mordecai said, and they start to walk off. "Wait. Me know you work hard to help, but me not civilized." The caveman said. "Huh?" Rigby asked.
"You forgot something." The caveman said. "We did? But.... I could have sworn we got everything. I even went over some extra things with Thomas. What else could we be forgetting?" (Y/n) asked as she looks over all the topics she had written on her notes. He goes to the chalkboard and writes "love" "oh..." (Y/n) said. "Love?" Rigby asked, and Gregg nods. "Me submit that I can't be truly civilized until me find other half." Gregg said.
"I don't know. Is there enough time to find it before our meeting with Benson?" Mordecai asked. "Certainly." He replied. Gregg leads (Y/n), Mordecai and Rigby through it, holding a flaming torch. "Her name Diane." He bangs on the side. "She frozen with my people." The three stop. "How many of you were there?" Mordecai asked. Gregg smashes a breakable wall, and they continue. "We were many." Gregg is standing before many blocks of ice with people concealed in them.
"Whoaaaa." The trio said. The three walk across them. "Oh Gregg, I'm so sorry." (Y/n) said, referring to his frozen family. "How do we find her?" Mordecai asked. "It will be easy. She only cavewoman here. Her beauty sine like star." He stops at the sight of the mentioned cavewoman. "There she is. My Diane." Gregg said. "Are you sure you wanna do this? Her forehead looks pretty big." Mordecai punches Rigby. "Ow!" He said. Gregg holds the torch up, causing Diane's block of ice to start melting. Later they are back at Pops' house. "Diane. How I have missed you." Gregg said.
Diane is sitting on a chair with a towel wrapped around her as she and Gregg are having a conversation. "Eh?" She asked. "My love thousands of years, and today begins anew. (Y/n), Mordecai and Rigby give us an hour to catch up. What do you want to do?" Gregg asked, and she only grunts. "Oh! We can't do that. It's more civilized time, now." Gregg said. She makes grunting noises as she is to say "You look strange!" "Well me may look strange, but it's a way of time. Me have to change. You will have to change, too." Gregg said, and she makes grunting noises angrily.
"It not so bad, look at these, pants." He shows his pants to her. "Pretty wild, huh? And that's television." A TV shows a car and a police car crashing into each other. Diane sees this and destroys the TV with a chair. "Oh, my!" He goes to her with a tray with two cups of tea. "Here, have some tea, calm you down." Gregg said. She makes grunting noises as she is to say "I don't know you anymore!") "What you mean you don't know me anymore?"
Diane slams the tray with the cups of tea into Gregg's face and she goes bursting trough the walls. "DIANE!" Gregg shouted. Diane runs as she is running through a road where a car is stopping and she punches the car, then another car stops as she continues to run to the park cave, holding a flaming torch, and she holds the torch up, causing the other cavemen's block of ice to start melting. Back to the room Gregg is looking at his reflection in the mirror. Gregg touches his forehead, making a realization who and what he is. He slams the objects into the floor until he calms down and breathes. "What am I?" Gregg asked. The trio enter the room.
"Gregg? Where's Diane?" (Y/n) asked. "We... we going through some stuff right now." Gregg said. "Benson's waiting." Mordecai said. "Me not ready." Gregg said. "But you'll go to the pound if you don't." (Y/n) said. "There are only two things that happen there, and you don't want them." Rigby said. " You'll do fine." Mordecai said. Gregg inhales and exhales. "Okay." He said. A crashing noise and Pops screaming are heard outside. "Pops?!" (Y/n) asked.
They go down to see what's going on, and the other cavemen Diane defrosted start attacking the park. Three cavemen attacked Skips' car while Skips retreats, then the other cavemen chase the people away. One caveman punches a fish in the fountain and grabs it, and two cavemen destroyed the fountain with a bench. Diane is riding on a white horse as the horse neighs and snorts. Diane snorts and looks up. She makes grunting noises, giving the other cavemen the signal to attack.
"Diane, call them off!" Gregg shouted. She grunts as to say "No!" "What do you mean "no"? Tell me why you do this." Gregg said. She grunts again and the horse neighs as she leaves with it. "Uh... We going through some stuff right now." Two cavemen destroy a wire post, then three cavemen attack the snack bar. Muscle Man closes the snack bar window as he and Fives are inside. A caveman snorts and struggles to open the door. "Oh no, bro!" He goes into a cabinet to hide,
then Hi Five Ghost phases through the cabinet. The three cavemen go inside the snack bar and start to trash it. Skips punches the cavemen, then he dodges the caveman's hit with his club, then another caveman tackles Skips. An animal control truck came with two dog catchers coming out of the truck and sees the chaos the cavemen are doing. One caveman appeared at the dog catcher's face and he grabs the dog catcher's arms and rips them. "I need a new job."
One cavemen is chasing the two kids as (Y/n), Mordecai, Rigby and Gregg run through the ruined fountain. "Caveman too strong and too many. You lose your jobs. Park destroyed. All my fault." Gregg said. "Come on, Gregg! We can do this. We just need to use our brains to think of something." Mordecai said. "Wait! In my time, my people value meat above all. Do you have meat?" Gregg asked. Later the quartet are in the cart with a big chunk of meat tied on the top of the cart as the cavemen start to chase after it. "It's working!" Rigby said.
As they stop near the basement, Gregg grabs the big chunk of meat and the three lead the cavemen into the meat locker where Gregg drops the big chunk of meat and the cavemen enter the meat locker to eat their meal. Gregg looks at Diane who is eating the meat. "Diane." He said. "Greg! Come on! let's go!" Mordecai said. "Come on! Get out of there!" Rigby said. "Yeah, come on!" (Y/n) said. Gregg thinks for a second. "Come on, Greg! What are you doing? You're running out of time!" Rigby said. "Get out of there! Come on! Get out of there!" Mordecai said.
"Yeah, it's not safe for you in there!" (Y/n) said. "Me sorry." Gregg closes the meat locker door. "Diane." He said. "What are you doing?" Diane asked in more grunting. Gregg removes his clothes. "What must be done. I'm sorry, Diane." Gregg said. "Gregg... I thought I lost you." She said in their language. "You almost did. But you were right. It wrong to give up self." Gregg said. "GREGG!" The trio shout as they are pounding the meat locker door. "Dude, unlock the door! Get out of there!" Mordecai shouted. "Thanks for helping me. But me not belong in modern world." Gregg said. "You could've been happy here!" Rigby shouted.
"No. No need TV, no need pants." Diane comes up to him. "Need Diane." As the other cavemen begin to freeze, Gregg and Diane begin to freeze, and Gregg sets the temperature to a higher level. "NO!!!" The trio shouted. As Gregg and Diane are about to kiss, he looks at (Y/n), Mordecai and Rigby and gives them a thumbs up until they are completely frozen. (Y/n),
Mordecai and Rigby begin to sniffle, tears in their eyes. "Gregg. Thanks for being our friend." (Y/n) said. As (Y/n), Mordecai and Rigby leave the basement, Benson approaches them. "Benson!" The trio said. "Benson, look, we..." (Y/n) was about to explain. "I saw everything. I had Greg all wrong. He gave up all for true love. In a way, he was more civilized than all of us. (Y/n), Mordecai, Rigby, clean up this mess. Do it... do it or you're fired." Benson leaves the scene, about to cry. "Greg was pretty cool. Do you think we should find another new friend?" Rigby asked. "Hmm. Nah. Three's good enough." Mordecai said. "Agreed." (Y/n) said.