(The episode starts at Clarence's house. In Clarence's room, him Sumo and Jeff playing a card game.)
Jeff: Haha. C-4.
Sumo: Missed! H-7!
Jeff: Dang it! Again! Are you peeking?
Sumo: Oh, quit your complaining and pay up.
(Jeff gives Sumo and package of gum. Then, Clarence gets out of his bed and pulls out a newspaper.)
Clarence: Guys, look! (reading newspaper) "Come one, come all for today's opening of the circus." (stops reading) It's something we have to go to all three of us alone.
Sumo: Yeah! Alone!
Jeff: Yeah! We... Alone? No, no, no. Clarence, remember last time?
Sumo: Jeff, we we're there. We're going. Whether we get in trouble or not.
(Later, the boys are at the circus. They get to a seat and watch the show. Sumo has a chunk of his cotton candy.)
Jeff: Look! The acrobats.
(Three acrobats jump and grab the rope of the tightrope. They pull themselves up and walk through a hoop of fire.)
Clarence: Cool, they're good. I wanna be one too.
Jeff: It takes years of practice. Besides if you did it now, you could get hurt.
(Sumo punches Jeff's arm.)
Sumo: You got hurt first.
Clarence: I'm gonna go get more snacks.
(As he walks down the stairs, he slips on melted popcorn butter, making him fall down the stairs. He falls on his head.)
(Jeff and Sumo run down the stairs and wake Clarence up. He awakens.)
Clarence: What happened? Where am I? Who... who are you?
Jeff: It's me, Jeff.
Clarence: Jef...Jeff who? Who the heck am I?
Sumo: Oh, no.
(At the hospital...)
Hospital Doctor: Good news is, your friend's still healthy body, bad news, he has a case of amnesia.
Jeff: Is there a chance he'll get his memory back?
Hospital Doctor: Well maybe in a few days. Or weeks.
(Later, Sumo and Jeff take Clarence back to his house.)
Clarence: I live here?
Mary: Let me guess... Nope, don't have a clue.
Jeff: He decided for three of us to go alone to a circus, then when we got there, he went to go get some more snacks and he slipped on popcorn butter.
Mary: I figured. Why can't you act like normal kids?
Sumo: Why can't you stop being a lame mom for Clarence?
Jeff: Look, Sumo. What she's trying to do is look out for Clarence; to make sure he doesn't get hurt, in trouble, killed, kidnapped or doing stuff he's not suppose to do.
Mary: Thank you, Jeff. Now, bring my boy's memory back. If he's like this forever, I'll have to raise him from the beginning again. And... and... if I... (crying)
Sumo: Alright, alright. We'll try to get him back, A.S.A.P..
Chad: Guys, whenever I try to talk to Clarence, he keeps running away. He's never been like this before.
Jeff: It's a long story. He slipped on popcorn butter on his way to get more snacks and hits his head.
(Sumo grabs Jeff and Clarence and heads out the door.)
Sumo: Don't worry, we'll get some help on this. And don't think of getting divorced.
Mary: But, we're not married!
(Later, at the Guy-Scraper...)
Dustin: So, you're telling us, you need our help to get Clarence's memory back?
Sumo: (pause) Yes.
Nathan: Well, you've come to the right people. We know a few things about him...
Dustin: ...as well as the times we hung out with him.
Nathan: First things first, we take him to the places he's been.
(A montages starts. The boys take him to the Pizza Swamp. Clarence shakes his head. They take him to Bendle Park. He shakes his head again. Then, the Pizza Shack. He shakes it again. Then, they go to a bunch of places he's been at. But still he has no memory of any of these places. Back at the Guy-Scraper, Sumo writes off every place they've been on a blackboard.)
Sumo: Well, the last place he's been around everyday is... school.
(A thunderclap's heard in the background. Later, the boys arrive at the school and walk in the hallway.)
Jeff: Well, anything?
(Clarence shakes his head.)
Jeff: This is the last place he's been around, guys.
Nathan: Then, stage two: We introduce him to his old friends.
Sumo: Yeah, that way he'll remember. And I'll have my old buddy back.
Jeff: Well, let's get to class.
(Sumo kicks the classroom door open.)
Ms. Baker: Oh, Sumo. Use the door next time.
Sumo: We need your help. Clarence has lost his memory.
Dustin: He's in limbo.
Clarence: They need me to see those friends of my I can't remember.
Sumo: Line up?
Jeff: Why not?
Nathan: Line up!
(Everyone lines up. Clarence looks at Kimby first.)
Kimby: ...then, you showed me and my friends how you do fun, later, you reacted to Malessica's words on not having the chance to tell Jeff she loves him. After you di...
(Two hours later, they wait. Then, Clarence comes out.)
Sumo: That's it! I give up.
Jeff: Sumo! Come back! We need to keep trying!
Sumo: No! See the signs! It's no use!
(Sumo walks out the door.)
Jeff: I'm afraid it's no use, guys. We've tried everything.
Nathan: Not everything.
Dustin: Our last subject is...
(He whispers in Jeff's ear.)
Jeff: No way, guys! I don't wanna hurt him. There's gotta be another way.
Clarence: No, Jeff. I've had enough! I'm going home.
(He walks away.)
(Later, Sumo puts a bunch a photos of Clarence and him in a box.)
Sumo's Sister: Sumo, why are you putting your photos of you and you friend in that box?
Sumo: Because, he's lost his memory. So, I'm making a new start. Pretending I've never met him.
(Clarence comes in Sumo's room.)
Clarence: Hey, Sumo. You want some chocolate ice cream at the ice cream shop?
Sumo: No thanks, Cla... Wait, how did... Did... Did you get your memory back?
Clarence: Yep. From a little incident.
(A flashback shows Clarence walking by Belson's house, as Belson holds a bat playing baseball by himself.)
Belson: Hey, Clarence. (Clarence says nothing back. He runs up to him.) Hey! Hey! Stop! What the heck? You didn't say hi to me. You never stopped saying that ever.
Clarence: Look, don't get mad a me. I was in a hurry, and I don't talk to strangers.
Belson: That's it!
(He hits him on the head with the bat.)
Clarence: Ow. Hey, I'm back! Oh, hey, Belson. How are you? Who hit me with something real hard.
(He hits him again.)
Clarence: Who are you again?
Clarence: Oh, so you're the one!
(The flashback ends)
Clarence: He had a bit of a temper.
Sumo: Why didn't you tell the guys?!
Clarence: I just wanted to have a few more days with myself.
Sumo: Well, it's time to get them happy you're back!
(He calls Jeff.)
Sumo: Jeff, Clarence got his memory back!
Jeff: Yes! How?
Clarence: Belson hit me with a bat.
Sumo: At least a hit on the head worked and gave us our friend back!
Jeff: Well, can't argue with that. (He hangs up.)
Clarence: So, wanna go ride down a hill in our wagon?
Sumo: Well, heck yeah.
(They both run outside, get their wagon an head for the hill. A tree has a carving saying, "Clarence, Sumo & Jeff - BFFs 4-Ever!" Cut to black.)