(Episode begins in outer space. We zoom in as the words 'Party Horse Planet' appear. Cut to a place on the planet called The Salt Lick. Ponies are partying all around, including Party Horse 42699. A female horse taps him and points to the exit. Outside the club, She gives him her necklace, waves him goodbye and leaves. Party Horse 42699 fell on his legs. Scene cuts to the Park)
Mordecai: We did it, dude! We mowed the entire lawn with out taking a single break! You wanna go get some lunch?
Rigby: Aw yea-uh, I do! Nothing on Earth's gonna stop us from getting some lunch! Huh?
(They see a spacecraft falling out of the sky and lands on the lawn, creating a big hole)
Mordecai and Rigby: Party Horse! (They walk towards it as they chant) Party, party, party, party, party, par... (the spacecraft opens) Huh?
Party Horse 42699: (sniffles) Oh, Chrissy! (cries; Scene cuts to the house where he is lying on the couch and Mordecai and Rigby are standing there.) UUUUUUGGGHHH!
Mordecai: Dude, what happened to you?
Party Horse 42699: Chrissy happened, man, she dumped me, and she'll probably never talk to me again.
Rigby: That's rough, man. What went wrong?
Party Horse 42699: Augh! It's all her dad's fault. He always telling her my partying is "compulsive" and that i'm a "danger to myself and others." I tried to talk to my bros on Party Horse Planet for advice, but they just duct taped me to a flagpole and put my underwear down. After that, I came to Earth hoping you dudes can help me.
Mordecai and Rigby: Wooooaaaaahhhh...
Mordecai: Uh, don't worry, dude, we'll help you get your girlfriend back.
Party Horse 42699: You will?
Mordecai: It's easy, you just gotta get something nice to show her you care about her.
Rigby: Yeah, man, the mall has like 20 stores that only sells stuff for guys who need to apologize to their girlfriends. With our help, you'll be back in the saddle in no time.
Party Horse 42699: Dude, saddle jokes, not cool.
(Scene cuts to the mall in a quick mini-montage where Party Horse 42699 is partying in a dress store with a disco ball, in a sunscreen store with two bottles of sunscreen, in a clothes store with three purses and in a pet store with a bird. Scene cuts to the spacecraft in the hole)
Party Horse 42699: (carrying flowers, a box of chocolates and jewelry) Thanks a lot for your help, guys. Sorry you can't ever go back to that mall again.
Rigby: Eh, you only ruined like seven stores with your partying.
Mordecai: Good luck, man. Let us know how it goes.
Party Horse 42699: Oh, you know I will!
(He gets into his spacecraft and leaves as Mordecai and Rigby cough)
Rigby: Chrissy's gonna love those presents.
Mordecai: Yeah, you can't go wrong with jewelry, flowers and chocolate, every guy knows that.
(They look around the hole)
Rigby: Benson's gonna be really mad about this hole.
Mordecai: I'll get the shovels.
8 Hours Later
(They finished digging up the hole)
Mordecai: And done.
Rigby: Phew! Now like I was saying before about lunch, nothing on Earth is gonna...
(The spacecraft comes back, creating another big hole as Mordecai and Rigby scream; the spacecraft opens, confetti shoots out and Party Horse 42699 comes out)
Party Horse 42699: Dudes! Chrissy did not like the presents!
Mordecai: But every guy knows you can't go wrong with jewelry, flowers and chocolate.
Party Horse 42699: I repeat, the presents were a major fail. She said that stuff is what guys think girls want and all those presents did was prove I was thinking about some generic idea of a girl, and not her specifically.
Rigby: That's so complicated.
Party Horse 42699: After Chrissy negged on your presos, I panicked and made her a mix-tape of dope party jams called "Base in Your Face", and for some reason, that was a bust, too.
Mordecai: But that sounds like a really good mix.
Party Horse 42699: I meant duh! Augh!
Rigby: Sorry, buddy. I guess we need a female prospective if we're gotta crack this nut you call Chrissy.
(Circle-wipe transistion to Eileen's House)
Eileen: So let me get this straight, you're a Party Horse from another planet and you need our help to get your girlfriend back.
Party Horse 42699: Yes.
Eileen: Have you've tried talking to her, just being real?
Party Horse 42699: Real?! I'm the realist there is! Check this out. (starts partying) BOOM!! That's real.
Eileen: Um, let's try some role playing, maybe?
Party Horse 42699: Okay.
Eileen: Margaret, you be Chrissy, Party Horse, you be you, and go.
Party Horse 42699: Don't do me like this, Chrissy, we're a perfect match! With that body and these abbs, we're the hottest couple on Party Horse Planet.
Eileen: First of all, wow, but you could focus on something besides her looks?
Party Horse 42699: Hmm, well, she dedicates herself to her interest, I think that's cool, and I like that she's in to art.
Eileen: Good, this is good.
Party Horse 42699: And I guess there's the way she elevates my very being and makes me wanna be a better person.
Margaret: Party Horse, that was perfect. Call Chrissy and tell her exactly what you just said.
Rigby: Or you could cry like Mordecai did after CJ-- (Mordecai punches him in the arm) OW!!!!
Party Horse 42699: Thanks, guys. I'm gonna call her. (Pulls up a ball-like holographic phone, dials Chrissy and calls her) Chrissy!
Chrissy: Party Horse, i'm sorry, but...
Party Horse 43699: Wait. I-I have something I need to say. Chrissy, I think you're really cool and your art skills, they-they always amaze me. You're like the castle of drawing girls stuff on sleeping dudes' faces. Just give me one chance to prove that partying doesn't control me. Let me take you out on a nice quiet dinner tonight. No base drops, no hangs property damage, just you, and me, and our thoughts.
Chrissy: That's... actually a really nice idea.
Party Horse 42699: It is?
Chrissy: Okay, Party Horse, one date. Tonight. Last chance.
Party Horse 42699: Yes! You won't regret this! (A call from another Party Horse named Charlie calls) Oop. Call waiting. One sec, babe. (He calls Charlie)
Charlie: Brah, lumberjack party tonight at Chad's pad where Chad, Brad and Tad are going and matching plad.
Party Horse 42699: Dude, that sounds rad! I'm in! (Charlie's call ended and back to Chrissy's call) Chrissy, I know I said no more parties tonight, but there's a party tonight!
Chrissy: You blew it, Party Horse. Goodbye. (She hangs up)
Party Horse 42699: Huh? (Another incoming call occurs) Oh, phew! Chrissy, I thought you... (Principal Party Horse calls him) Principal Party Horse?!
Principal Party Horse: I told you to stay away from my daughter! If I see you again, you're glue! (His call ends)
Rigby: That guy really doesn't like you, huh?
Party Horse 42699: Awww! Augh! (He collapsed on Eileen's couch) It's not fair! I didn't asked to be born this way. If only there was some way to exhaust this burning party star inside of me.
Mordecai: (gasps) That's it, dude! We gotta party the party out of you and then you can get Chrissy back.
Rigby: Aw, yeah! You gotta party so crazy you never wanna party again.
Party Horse 42699: (gasps) Were going to Party Horse Planet!
(Party Horse 42699 crashes through Eileen's door as the guys are going to Party Horse Planet)
Eileen: So we'll see you guys later.
(Scene cuts to outer space where the spacecraft lands on Party Horse Planet, creating a hole, then Party Horse 42699, Mordecai and Rigby come out.)
Rigby: So these pods really don't have a way to land safely?
Party Horse 42699: Nah, all the scientists are too busy partying to figure it out. (pulls out a Party Horse brochure and shows them the map) Okay, here on Party Horse Planet, there's a party on every block. You'll see that party houses are indicated on the map by a party hat. The way I figured it, we're gonna hit them all tonight if there's any hope of partying my party out.
Mordecai: Wow, you're so well-prepared when it comes to parties.
Party Horse 42699: Oh, this is just the local news paper. I actually have terrible special skills, so let's just start here.
(They come to the first party house, Party Horse 42699 knocks on the door and the Colonial Party Horse answers it)
Colonial Party Horse: Dudes, welcome to the Colonial America Party! Come inside and get your Delaware on!
Party Horse 42699: WHOOOOOOO!!!!!!!
(They come to the second party house)
Leprechaun Party Horse: Amigos! Cinco De Mayo St. Patrick's Day Fiesta! (Eats his nacho)
Tux Party Horse: Bros, welcome to my Purple Prom! Rental tux is in the back.
Toga Party Horse: Opa! Tie-Dye Toga Party!
Bathing Suit Party: Sandy Bathing Suit Party!
Makeover Mainess Party Horse: Makeover Madness Party!
Mom and Dad Party Horses: Family Portrait Fest! (She takes a picture)
Aerobics Party Horse: Aerobics!
Lobster Party Horse: Lobster Party here!
(Five Party Horse heads spin around as they go to so many parties, then Party Horse 42699, Mordecai and Rigby come out of a party horse. Mordecai is wearing a pirate hat, two necklaces a toga and a floatie, and Rigby is wearing a pirate hat, a red-squared shirt and white pants)
Party Horse 42699: Ha ha ha ha ha! That was awesome!
Rigby: Did you get the party out of you yet, Party Horse?
Party Horse 42699: Aww, I still wanna party! Have we done all of the houses yet?
Mordecai: (looking at the map) Uh, yeah, I think that's all of them.
Rigby: Uh, what about that one? (Points at Chrissy's house with Principal Party Horse and Reverse Psychology Horse at the doorstep)
Party Horse 42699: Chrissy's house!
Principal Party Horse: Come one, come all to my epic Back-to-School Party except students. Everyone except students is invited. You sure this is gonna work, Reverse Psychology Horse? (Reverse Psychology Horse shakes his head) But... (He narrows his eyes) Ohh!
Party Horse 42699: Yep, going to that party seems like a bad idea. But maybe, forbidding partying at the home of my worst enemy and ex-girlfriend is the only way to get my partying out once and for all. (sniffs) Chug some waters, bros, 'cause we got one more hiz-house to hiiit!
(They went to Chrissy's house and finds school Party Horses inside this house)
Party Horse 42699: Augh! A school theme? I partly here forget about school. I don't know, you guys. So far, I don't feel any diff... (He bumps into Principal Party Horse) Oh, no.
Principal Party Horse: Well, well, if it isn't... (Mordecai and Rigby look at each other worriedly) Party Horse! (Shakes hooves with Party Horse 42699)
Party Horse 42699: What?
Principal Party Horse: I did some thinking after our last chat, and I realized I was wrong. All this I've been trying to teach you about knowledge and responsibility when I should've been letting you party. I guess what I'm trying to say is party on, Party Horse, party on.
Party Horse 42699: Wow! Thanks, Principal Party Horse.
Principal Party Horse: And one word of advice before I let you go. (Points to a party palace booth) Whatever you do, do not use the Party Palace Booth I had set up for this party.
Party Horse 42699: Why not?
Principal Party Horse: It's much too much partying for you, Party Horse, it's the best party in the universe in a box. Just thought I'd warn you. Well, goodbye. (He leaves)
Party Horse 42699: Dudes, I am so confused.
Rigby: Go for it, man. Maybe, this is the last bit of partying you need to get the party out of your system for good.
Party Horse 42699: I'll do it. (He goes into the Party Palace Booth) Aw, yeah! Get ready for the new me, Chrissy! (He presses a button and the alarm goes off) Huh? What is that?
Voice: Party Horse detected. Initiating lockdown.
(The door is locked and Principal Party Horse appears, laughing evilly)
Principal Party Horse: The reverse psychology worked perfectly! I've finally trapped Party Horse!
Part Horse 42699: So, wait, hold on, I'm sorry, is there, like, not a really cool party in this box?
Principal Horse 42699: You fool, this isn't a party in a box, it's a box that sucks the party out of your bones permanently. (Party Horse 42699 gasps in shock) Prepare yourself, Party Horse 42699, your party is about to get pooped.
(He touches the lever, Mordecai and Rigby gasp and Chrissy appeared, running to Party Horse 42699)
Chrissy: STOP!!!! Dad, stop it!
Party Horse 42699: No, Chrissy, if this is what will stop me from partying, then I'll do it for you.
Principal Party Horse: He said he'll do it!
(He turns on the booth, and red lighting zaps on Party Horse 42699, losing his party essence as he screams and Chrissy covers her eyes)
Chrissy: Oh, I can't watch! (looks back) Party Horse 42699?
(The booth sucks Party Horse's party out of his bones, party essence pours in a cup, the door opens, and Party Horse 42699 comes out of the booth, and is now a Non-Party Horse)
Party Horse 42699: I... like eating sandwiches and... fantasy football.
Mordecai and Rigby: Eugh!
Chrissy: Uh, what?
Principal Party Horse: (as he takes the cup full of party essence) At last, I've done it! I've broken Party Horse!
Party Horse 42699: Well done, Principal Party Horse, sir. It this what you wanted, Chrissy?
Chrissy: No! I've been trying to tell you all along, but you never even chilled out long enough to listen to me! I just wanted you to take it down a notch.
Party Horse 42699: That's all? Well, I can do that.
Chrissy: (taking the essence cup from her father) Change him back, Daddy! (gives the essence to Party Horse 42699) Drink it up, babe. Come on!
(Party Horse 42699 smiles, drinks the essence and he starts to change)
Party Horse 42699: Here you go, babe. I'm taking down a notch for you. (He spills out the rest of the essence)
Chrissy: (wide-eyed) Aww, babe!
(Party Horse 42699 drops the essence cup, which breaks, and is fully back into his non-stop partying self)
Party Horse 42699: Party Horse is back in business!
Chrissy: (giggles) You sure is.
Mordecai and Rigby: WOOOOOOOOOOAAAAAAAAAAAHHHHHHHHH!!!!!!
Principal Party Horse:(groans)
Reverse Psychology Horse: It is about ze long game.
Party Horse 42699: Thanks for all your help with this, guys. You have a life-long invitation to party with me and my girlfriend. (they giggle)
Mordecai: I'm good.
Rigby: That's alright.
(Scene cuts to the Park where Benson finishes digging up the hole)
Benson: (sighs) There's nothing...
(The spacecraft lands again, creating another big hole as he screams and growls; Mordecai and Rigby look around the hole and looks up at Benson, who is also looking at the hole angrily. The guys are shocked at this, and the spacecraft leaves the hole, flying back up into space.)