SpongeBob: [as he runs to Patrick's rock] Patrick! Patrick! Oh, Patrick! Are you ready to go jellyfishing? [Patrick comes out of his rock with a box, doing an acrobatic trick]

Patrick: Oh, boy, am I!

SpongeBob: Here's your net. [Patrick glances at his box] Well, come on, Patrick! The jellyfish don't catch themselves.

Patrick: First, I have to put away my secret box.

SpongeBob: Secret box? You never told me about your... secret box! [tries to peek in the box, but Patrick pulls it away]

Patrick: Hey, hands off, PeepingBob! This here is my secret box! Besides, if I showed you what was inside, it wouldn't be a secret anymore. Duh! [opens the box, laughs at it, and shuts it as SpongeBob tries to peek it] Oh, SpongeBob… if only you could see what's inside my secret box, it would change your life! [SpongeBob gets behind Patrick to see what's inside the box, but Patrick holds it to himself]

SpongeBob: It's okay, Patrick, I know all about secrets.

Patrick: You do?

SpongeBob: I've got a gazillion secrets!

Patrick: Like what?

SpongeBob: Well, it's no secret that the best thing about a secret is secretly telling someone your secret, thereby secretly adding another secret to their secret collection of secrets. Secretly. [Patrick drools as the top of his head has lightning bolts coming out of it, showing that he couldn't understand the whole sentence]

SpongeBob: You wanna hear one of my secrets?

Patrick: Do I?

SpongeBob: Uhh... Let's see... [runs up to Patrick] Did you know that you're my best friend? [runs away]

Patrick: No... way. Oh, let's hear another one!

SpongeBob: Okay. Uhh... Secretly... I'm a little bit naïve.

Patrick: Wow! I'll never look at you the same way again, SpongeBob. Gosh. [SpongeBob clears his throat and taps on Patrick's box] Tell me some more secrets!

SpongeBob: Okay. I love my job at the Krusty Krab, I sleep with my shoes on, I like jelly on both sides of my toast, I've got an overdue library book, I think jellyfishing and bubble-blowing are the... [transition to SpongeBob still telling secrets as Patrick lays his head on the box] ...overbite. I've never been late for work, I've said the word "fancy" in conversation, I like to dance to loading zone announcements, I still don't have my driver's license. I'm a little bit on the short side. And I'm wearing three pairs of underwear, right now. [he shows his three pairs of underwear to Patrick]

Patrick: Gasp. I never would have guessed.

SpongeBob: Now will you show me what's inside your secret box?

Patrick: No, SpongeBob! It's for me to know and for you to never find out. You may be an open book, SpongeBob, but I'm a bit more complicated than that. The inner machinations of my mind are an enigma. [imagines a carton of milk spilling itself]

SpongeBob: Oh, yeah?! Well, I got plenty of secret stuff, too! Uh… [close-up of SpongeBob's socks] I've got my secret socks on. [runs away and comes back with Gary's bowl] And my secret Gary's bowl! [runs away then comes back, pushing his television] My secret TV! [turns on the TV] And my secret TV channel. [the TV shows an off-air color bars screen] What do you think of that, Patrick? Patrick?

Patrick: [giggles, then laughs loudly after a gander at the box and then stops to breathe. Then he looks again and laughs harder and wildly. Then he stops to breathe] Maybe if you saw what was inside, you'd know why it has to be secret. [shows the box to SpongeBob] Inside this very box is the most secret-y secret of all of secret-dom and I am its sole witness! It's a heavy burden, SpongeBob, but nobody must know the mystery of the box. [SpongeBob tries to peek inside the box, but Patrick slams it shut] Nobody! Not even… Squidward's house. [scene zooms out to show Squidward's Tiki Head home looking down at SpongeBob and Patrick, who notice this before it goes back to normal] It's a full-time job. I'm constantly on the alert. You never know when someone's gonna… [gasps when he finds out his box is gone. The scene cuts to a laughing SpongeBob running with Patrick's secret box, but then he bumps into Patrick's belly] SpongeBob, what do you think you're doing?! That's my secret box! Now, hand it over!

SpongeBob: [struggles with Patrick on the box] But, Patrick, I must know the secret!

Patrick: [struggles with SpongeBob on the box] For the last time, SpongeBob, no!

SpongeBob: Come on, Patrick, just a peek?

Patrick: Never! [SpongeBob and Patrick strain as they fight over the box. Eventually, SpongeBob's arms pop off and he gasps] So, it's come to this. And to think that we joined the Best Friends Forever Club! [shows his finger with the ring on it and then the camera zooms in on the ring. He grabs one of SpongeBob's arms and points it at SpongeBob] Listen up, SpongeBob SecretStealerPants! [as he pokes SpongeBob's nose with his arm] If you ever come near my secret box again, we won't be friends anymore!

SpongeBob: But... we're supposed to be... [his eyes get big and sad] friends forever. [flashback to SpongeBob and Patrick as babies in a crib laughing, then we see them as kids riding on a bike, then as they are now, riding a bike, then as older men in rocking chairs, then we see a shot of two gravestones with their names and we hear SpongeBob and Patrick still laughing, but they are buried. The flashback ends.] I feel so filthy! [starts to cry] I have soiled our friendship garden! I just couldn't help myself! [jumps on Patrick] I know it's your secret! I promise to respect that! Oh, please forgive me, Patrick! Please!

Patrick: Well... I guess it's not all your fault. After all, this is a pretty great secret. I mean, how could you resist the greatest secret ever? [we see a close-up of Patrick's box] The most amazing... [as he sticks the box in SpongeBob's eyes, the eyes pop out of him and then back in] mysterious... powerful secret in all Bikini Bottom. [his eyes are glued to the box for a moment, and then goes back to him]

SpongeBob: So, what do you say, buddy? Friends?

Patrick: Friends. [they shake hands. Cuts to a night view of SpongeBob's house, then inside as SpongeBob talks]

SpongeBob: What could be in that box that Patrick doesn't want me to see? Maybe it's the world's only albino jellyfish... [slides down in his bed] or maybe Patrick's a master jewel thief and it's full of diamonds. [sits up] Or maybe Patrick's a deranged maniac who keeps his victims' severed heads in a box! [hides himself in the blanket and shivers] Or even worse... Maybe it's an embarrassing snapshot of me from the Christmas party! [screams, then hurls himself towards the bedroom window] I've gotta find out what's in that secret box! I'm not gonna rest till I do! [SpongeBob's face pops off and sticks onto his back] That's it! How do you look in a secret box? [jumps off the window] Secretly, of course; I'll just take the box while Patrick's sleeping, look inside, and before Patrick even has time to notice, I'll slide it back. [turns around to show only his nose, then turns back around] Patrick won't know, and I'll have my own little secret! Good idea, eh, Gary? [Gary narrows his eyes]

Gary: Meeh… No. [cut to the outside]

SpongeBob: Oh, what do you know? You're a snail! [sneaks over to Patrick's house, puts on gloves and a ski mask, crawls up the rock with his back, and tears him in half and gets both halves under the rock. He then lands and notices Patrick. He then screams gibberish, drools and SpongeBob hides behind the portrait of SpongeBob and Patrick. SpongeBob then peeks and then the wall starts to crack. Patrick mumbles, the wall breaks even more and then the nail falls off. He then grabs the nail with his foot and puts it back.]

Patrick: [as the camera zooms in on the box] Seee... cret.

SpongeBob: [thinking] I got to be more quiet. I don't want to wake Patrick up. [slides down the wall from the portrait and makes a loud noise upon touching the floor. Patrick stretches and then goes back to sleep. SpongeBob then lifts his leg and then Patrick makes another noise. He then tosses himself over on the bed. SpongeBob puts his leg down, which makes a loud noise]

Patrick: Duh... who's there? [mumbles then goes back to sleep.]

SpongeBob: [talking to his foot] Shhh! [steps on a potato chip and makes a broken glass sound]

Patrick: Eh?! [gibberish] Who's that?! [Patrick is back asleep. SpongeBob sweeps his sweat drops off him and they land, causing a loud splash sound.] Mmm... water. [licks his mouth dry, then tosses himself on the bed. SpongeBob takes another step and makes an "Aooowga!" noise. He then steps again, making a loud machine gun noise. Steps again, making the sound of an elephant. He then stretches his leg near the side of the bed, which sounds like a speeding car, then takes the step, making the noise of a car crash. He then peeks above Patrick to see the box. He gets ready to reach for the box, but Patrick takes the box before SpongeBob could grab it. He then slides onto Patrick, grabbing the box] Good old secret box. Let's see what's inside. [opens SpongeBob's mouth and pulls out his tongue, then laughs and lets go of his tongue] Nighty-night, boxie. [puts SpongeBob on the side of the bed. SpongeBob gets off the bed and then trips on a shoestring, causing him to bounce around Patrick's house, making a lot of loud noises until his head hits the wall, causing the portrait to fall off the wall, hitting him in the head, breaking the portrait in half. The box then lands on SpongeBob and makes a loud noise. The scene cuts back to Patrick, who, despite all the noise, continues to sleep]

SpongeBob: Gee, Patrick sure is a heavy sleeper. [Patrick wakes up]

Patrick: Huh? Who said that?! Who's there?!

SpongeBob: Uh…

Patrick: It's the Clam Burglar! And he's stealing my secret box! [runs up to SpongeBob] Hand over the goods, Secret Box Bandit, and prepare for the most unpleasant pillow fight of your life! [readies his pillow like a shotgun, ready to attack him]

SpongeBob: Wait, wait, wait, Patrick! Stop! [takes off his mask] It's me, SpongeBob!

Patrick: [stares at him while clueless] Nice try, burglar, but SpongeBob's my best friend, and he'd never steal from me.

SpongeBob: No, really, Patrick! Look! [Patrick gasps. SpongeBob presses a button on the ring]

SpongeBob and Patrick BFF Ring: It's the Best Friends Forever, Best Friends Forever Ring!

Patrick: Our friendship ring! It is you! [crying as he covers his face with his pillow] How could you do this?!

SpongeBob: If it makes you feel any better, I haven't looked inside. [throws the pillow away and snatches the box out of SpongeBob's hands]

Patrick: [with a tear coming out of his eye] That's it, SpongeBob! You have crossed the line. As of right now, this friendship is over!

SpongeBob: [gasps and tears up] Really?

Patrick: Nah, you can look inside it if you really want to.

SpongeBob: Okay! Oh, this is one of the most exciting moments of my life! Well, here it goes! [he lifts the lid off the box] Huh?

Patrick: Well, didn't I tell ya? [we see a string inside the box] Isn't it great?

SpongeBob: It's just a string.

Patrick: A secret string!

SpongeBob: Boy, when you're right, you're right! That's some secret box you've got there! Yeah! Thanks for showing me that! [puts the lid back on the box] Well, good night, Patrick. See you tomorrow!

Patrick: Good night, SpongeBob! [SpongeBob pops out of Patrick's house]

SpongeBob: I should've known! It was just a piece of string all along! [laughs] Wait 'till I tell Gary!

Patrick: [laughs menacingly] Good thing he didn't pull the secret string, opening the... [a secret compartment opens] ...secret compartment of my secret box... [takes out a photo] ...revealing one embarrassing snapshot of SpongeBob at that Christmas Party! [cut to the Bikini Atoll] Merry Christmas, SpongeBob! [laughs as the screen fades to black, ending the episode]