(The episode begins with a temple with a volcano behind it.)
Announcer: A thousand years ago, in the most ancient of dojos, the most delicious sandwich in the world entered our realm.
(The sandwich flies out of the volcano and a man on a sidewalk catches it and eats it.)
Announcer: The only problem is if you eat it wrong... You die.
(The man explodes. Then the scene cuts to a shirtless man holding the sandwich.)
Announcer: Fortunately, men discovered the correct way to eat it.
(The man's pants get ripped into jean shorts and a mullet wig appears on his head.)
Announcer: With cut-off jean shorts and the proper haircut.
(The man holds the sandwich up, then the scene cuts to a montage of random guys with jean shorts and mullets eating the sandwich in different ways.)
Announcer: (Sings) Death Sandwich! Death Sandwich! If you don't eat it right, you're gonna DIE tonight! It's the Death Sandwi-i-i-i-i-i-ich!!
Announcer: So come on down to "Death-Kwon-Do Pizza & Subs".
Man: (Points to the camera) And remember, eat it right or you die!
(Mordecai and Rigby look at each other and run out the door; scene goes to "Death-Kwon-Do Pizza & Subs" in the Two Peaks Mall; Mordecai and Rigby run to the counter.)
(Sensai turns around, wearing an apron and is holding a notepad and pen.)
Sensai: How may I help you? (notices Mordecai and Rigby) You guys?!
Mordecai: Haha, hey.
Sensai: So, you have the nerve to look me in the eye after nearly destroying my Death-Kwon-Do business.
Mordecai: Look, we're sorry about that, man. But hey, it looks like you really bounced back. Got this whole sandwich gig going on, looking good.
Sensai: (Sighs) You're lucky forgiveness is one of the many virtues of Death-Kwon-Do. So what can I get you?
Mordecai and Rigby: The Death Sandwich!
Sensai: To receive the Death Sandwich, you must first sign this waiver of death.
Mordecai: Yeah, sure. Let's do it.
Rigby: Why not?
(Sensai shows the waiver saying "You can't sue me" and they sign it.)
Sensai: Alright, I'll have that out for you in a minute.
(The Sensai backflips to behind a table and makes the Death Sandwich and making noises at the same time; the Sensai puts his hands together and brings it to Mordecai and Rigby.)
Sensai: One Death Sandwich.
Mordecai and Rigby: Yeah-yuh!
Sensai: But, remember. If you don't eat it right, you die.
Mordecai: Yeah, yeah. Wear mullets and jean shorts. We got it.
(Mordecai grabs the sandwich; scene goes to them walking into the kitchen.)
Rigby: Man, I'm about to tear this thing up!
(Mordecai and Rigby laugh as they open it.)
Mordecai: Whoa, wait. We gotta get mullets and cut-offs first.
Rigby: Aw, yeah, yeah, yeah. Now you're talking lunch!
Mordecai and Rigby: Death Sandwich! Death Sandwich! Death Sandwich!
(Mordecai and Rigby leave the sandwich on the table and walkout of the kitchen; Benson walks in, whistling and sees the sandwich on the table.)
Benson: Well, well, well. Looks like it's time for a little payback. Let's see how they like it when somebody else steals their sandwich.
(Benson takes a bite of the sandwich. Mordecai and Rigby enter the kitchen wearing mullets and cut-off jean shorts.)
Mordecai and Rigby: Death Sandwich! Death Sandwich!
Rigby: Aw, what?
(Benson coughs. He has turned green in the face and is choking and gagging.)
Mordecai: Whoa, are you alright?
Rigby: It really is a death sandwich.
Benson: Death sandwich?! Why would you buy something that kills people!?
Rigby: Why would you eat somebody's sandwich?
Mordecai: Come on, guys. This is serious. We gotta get Benson a cure from the Death Sandwich before it's too late.
(The scene transitions back to the Death-Kwon-Do Pizza & Subs.)
Mordecai: Dude, you gotta help us. Our boss ate the Death Sandwich wrong.
Sensai: What? How could this have happened?
Rigby: We left it in the kitchen, and Benson came and ate it.
Sensai: (Groans) It is clearly stated in the waiver that the Sandwich should never be left unaccompanied under any circumstances!
Benson: You didn't read the waiver?
Sensai: Now, if you would excuse me, I have a business to conduct. Good day, gentlemen.
Rigby: But our boss is gonna die!
Benson: If the Sandwich is so dangerous, then why don't you just take me to the hospital?
Mordecai: Yeah, you're probably right. Let's get outta here.
Sensai: (Groans) I'm afraid that would be a fatal mistake. (They all stop, then turn around.) Your boss is now far beyond the help of Western medicine.
Rigby: Well, then, what are we supposed to do?
Sensai: His only chance of survival now is to see my Sensei, the Grand Master of Death-Kwon-Do. He is the protector of the Sandwich of Life.
Rigby: What's the Sandwich of Life?
Sensai: It is the only known cure for the Death Sandwich. He will listen to your request, and if he agrees, he will let Benson have a taste. One bite from the sandwich will cure him instantly.
Mordecai: All right, let's do this. What's his address?
Sensai: I'm afraid it is not that simple. No mere outsider is allowed before the Sensei. I must accompany you on your journey. But time is of the essence. If your boss does not take a bite from the Sandwich of Life within six hours, he will die.
(Mordecai, Rigby, and Benson have a disturbed look on their faces. Sensai flips the sign around to say, "Be back in 5 minutes if death." He then drives off. In the car, Benson is choking and gagging.)
Mordecai: What's gonna happen to him if we can't get the Sandwich of life in six hours?
Sensai: His body will undergo six stages of agony while speeding towards his inevitable death. His face will turn green and he'll begin to choke.
Rigby: That's what was happening to him in the kitchen!
Sensai: Yes. Soon after, his face will start to burn.
Benson: Oww! It burns!
Sensai: Benson's intestines will begin to melt and leak out of his body. (Rigby scoots away from Benson.) He will shriek in pain, but no one will hear it, because his vocal chords will have long since evaporated. But then he'll regain his vocal chords...
Sensai: ...Only to cry out for mercy in ancient dialects long since forgotten.
Benson: I'm pretty sure you can go 65 here.
(Finally, the car stops at a temple nestled in the mountainside.)
Sensai: I'm gonna go request a meeting with the Sensei. You guys just wait here.
(He exits the car. He approaches the guards at the temple gates, but one of them punches him, knocking him down.)
Sensai: Okay, minor setback. I forgot to mention that me and the Sensei kind of had a falling out. (He drives away.) It's time for Plan B.
Mordecai: What's Plan B?
Sensai: (Opens the trunk) We sneak in and take the sandwich by force. Here, Benson. You're gonna need the power of Death-Kwon-Do. (He tosses a pair of cut-off jeans to Benson.)
Benson: What, I just have to put these on?
Sensai: Not quite. (He pulls out a razor, and then turns it on.)
(Sensai and the three park workers all have cut-off pants on. They all leap over a wall.)
Sensai: The Sandwich of Life is at the very top of the mountain. Come now. We move as one!
(They all run for the entrance, but one of the guards spots them.)
Temple Guard: Hey, stop!
(The guard rings the warning bell.)
Sensai: Quickly! Into the first chamber!
(They enter the temple and find themselves in a room with a pit filled with rows upon rows of thick bamboo poles. Paintings of tigers and cranes are on the walls.)
Sensai: Things will become increasingly more difficult as we approach the sandwich. Be ready.
(On the other side of the pit, three guards enter the room, each carrying a bladed weapon. The middle one steps forward.)
Guard: (Attack yell) ...I mean Step of Dea-a-a-a-a-aa-ath! (He plummets to his doom.)
Sensai: That reminds me. In this room, you must say, "Step of Death" every time you step, or you will plummet to your death. Almost slipped my mind.
(The remaining two guards start hopping from pole to pole, saying...)
Guards: Step of Death! Step of Death! Step of Death!
Mordecai and Rigby: Step of Death!
Guard: Step of Death!
Mordecai and Rigby: Step of Death! (They use a Death Punch on the guard.)
Sensai and Benson: Step of Death! Step of Death! (The final Guard leaps in the air, swinging his weapon violently. Sensai and Benson dodge out of the way.)
Guard: Step of Death!
Sensai: (Does a Death Kick) Step of Death!
Rigby: (Does a Death Flip on another guard) Step of Death!
(Benson then Death Kicks the guard.)
Benson: (Weakly) Step of De-e-e-eath!
(Then a montage shows the group going through the next couple of chambers. The second one has a bunch of guards carrying sickles who jump out of the trees. The group defeats them. In the third chamber, a bunch of guards riding motorcycles crash through the windows. They circle the group, whirling their meteor hammers. But the group uses their own weapons against them. Just as the group approaches the next set of doors, clouds of mist appear out of nowhere. Guards wielding sais attack them, but to no avail. Inside the fourth chamber, two guards slam the ground with their powerful axes, knocking everyone backwards. Mordecai and Rigby do a Death Jump and take out both of them. In the fifth chamber is a guard with clawed hands and wearing a hockey mask. The guard crosses his arms and multiplies before the group. But the guard and his duplicates are no match for the group.)
(Finally, the group approaches the mountain summit. By this time, however, Benson has grown very weak, and is now pleading in ancient dialects long forgotten.)
Benson: (Weakly) Agga dagga dume tu kara tu...
Mordecai: We're almost to the top, Benson. Don't give up yet.
Sensai: The Sensei is through that door. (The door opens to reveal the Grand Sensei floating above the tip of the mountain's summit. Two sandwiches are next to him.)
Mordecai: Is that your Sensei?
Sensai: Yes. And that sandwich right there is the Sandwich of Life.
Rigby: Which one? There's two of them.
Sensai: It's the on the organic multi-grain. Opposite, we have the deadliest sandwich known to man: the Double Death Sandwich.
Mordecai and Rigby: Whoooooaaa...
Sensai: Just let me address the Sensei. He might still be mad at me.
(They all approach the Sensei. Mordecai lays a weakened Benson down.)
Sensai's Master: You got a lot of nerve coming back here after what you pulled.
Sensai: Forgive me, Sensei...
Rigby: What did you do? (Sensai groans.)
Sensai's Master: I took him off the streets and raised him like my own son. He repaid me by stealing the recipe for the Death Sandwich and mass-producing without permission!
Sensai: I will accept full responsibility for my crimes against the school. But there is now a more pressing matter at hand. Our friend Benson is about to die from eating the Death Sandwich incorrectly. We humbly request that you bestow the Sandwich of Life upon him.
Sensai's Master: (Laughs) You must be a real fool. Did you honestly think I'd just hand over the Sandwich of Life? Kill them!
(Several guards wielding katanas jump in the air and land in front of the group. Mordecai and Rigby jump and avoid their katanas, but get captured.)
Sensai's Master: You don't deserve the powers of Death-Kwon-Do!
(The Grand Sensei spins a razor in the air and hurls it forth. Sensai manages to escape the guards' clutches and jumps to the ground just as the razor shaves off some of his hair. Mordecai and Rigby scream in anger and Death Flip, knocking the guards backwards. Then the Grand Sensei laughs wickedly as his outfit comes off to reveal a pair of cut-offs and wristbands. He takes the two sticks from his hairdo and lets it slowly unfold. As Mordecai and Rigby stare at their foe and the Double Death Sandwich, Sensai looks on. The Grand Sensei then hurls the sticks at Mordecai and Rigby, but the duo dodges out of the way, and the sticks hit the doorway instead.)
Mordecai and Rigby: Yaaa! (They start fighting the Grand Sensei. But the Grand Sensei has the upper hand and lands multiple blows while also blocking their attacks.)
Benson: (Weakly) Agga dagga... (Coughs) sanoubi...
Sensai's Master: (Laughs) He says that he forgives you. It's too bad he'll never taste from the Sandwich of Life. (He removes the cover from the Double Death Sandwich.)
Sensai: Sensei, no! Not the Double Death Sandwich!
Sensai's Master: Order up! (With an attack yell, he sends the Double Death Sandwich flying forward.)
(Sensai plays a few notes on his flute. He hands a small scrap of folded paper to a yellow bird, which hands it to Mordecai and Rigby. They unfold the sheet of paper and look at it.)
Mordecai and Rigby: (Gasp) The Bicycle Kick of Death!
(The Double Death Sandwich gets much closer.)
(He and Rigby do the Bicycle Kick of Death, deflecting the Double Death Sandwich. The sandwich flies smack into the Grand Sensei's mouth, destroying him. Rigby then removes the cover from the Sandwich of Life and tosses it to Sensai, who feeds it to Benson.)
Sensai: Come on...
(Benson is cured instantaneously, just as the mountain starts to rumble. A deep crevice suddenly appears on the ground.)
Rigby: What's happening?
Sensai: The mountain is self-destructing!
(The group falls through as the ground crumbles beneath them.)
Sensai: Use the Death Jump!
(The group uses a piece of crumbling earth as a boost and jumps out of the crevice. They all land safely in the car and start driving speedily as the mountain collapses behind them. Once they are safe, they all breathe a sigh of relief.)
Mordecai: Thanks so much. I don't know how we can ever repay you.
Sensai: I'll probably think of something.
(The scene transitions to the television. Mordecai and Rigby are on a commercial for the Death Sandwich.)
Announcer: So come on down to "Death-Kwon-Do Pizza & Subs" at the Two Pines Mall. And remember...
Mordecai and Rigby: (Point to the camera) Eat it right, or you die!