Episode starts in a skool classroom and the words DARK HARVEST appear. Scene goes through science room with bones, organs, and posters, then shows a jar with purple liquid and Fillerbunny in it. A teacher picks the jar up and places it on the windowsill. A red dodge ball breaks through the window and shatters the jar. The teacher looks mad. Happy music plays as skool children pass a red dodge ball to each other. It gets to one fat guy who throws it hard at Zootch.
Zootch: (hit by the dodge ball) Ugh! My organs! (doubles over in pain)
Zim: Rhahaha! Inferior (points at Zootch) human organs!
The ball is thrown at Zim. He spits and falls over too.
Zim: Oh, my squeedilyspooch! (holds his squeedilyspooch)
The scene cuts to Gaz, playing a game on a bench.
Dib: Squeedlyspooch? Did you hear that, Gaz? That's no human organ. Humans don't have squeedilyspooches!
Gaz: I've got a squeedilyspooch.
Dib: If only I had some way of looking inside his body...
Truck pulls up and a delivery man walks out.
Guy: I'm looking for a Mr. Dib? (looks at his clipboard)
Dib: That's me! (takes package and signs his name) It's my personal ex-scope! I ordered it from the back (takes out ex-scope) of Crops Circles Magazine.
Gaz: You had it delivered to skool?
Zim: (as Dib is observing Zim) Hey! Throw it over here you filthy stinking friends. (ex-scope shows ZIM's squeedilyspooch which is unknown)
Dib: Incredible! (Zim is heard yelling "HEY HEY HEY!" over and over) You see Gaz, to defeat my enemy I must study my enemy, then become my enemy, then move in with my enemy, then wear my enemy's clothes (Zim yells "I AM ZIM!!!" in the background) then-
Gaz: You're in my light.
Cuts back to the Ms. Bitters' classroom where the words "BUBONIC PLAGUE" are written on the board.
Ms. Bitters: So you see, Ring Around the Rosie refers to the horrible symptoms of a (pigeon flies in) terrifying disease. A disease which--- (pigeon coos and lands on Zim's head) a disease which (bird coos again) Zim!
Ms. Bitters: There's a pigeon on your head. You've got head pigeons. Get to the nurse before they spread to the other children.
Zim: Yes Ms. Bitters. (Walks towards door with pigeon still on his head.)
Ms. Bitters: No leaving the class without a hall pass, Zim.
Zim: Of course! (Walks over to Ms Bitters' desk and gets a collar hall pass.)
Ms. Bitters: If you leave skool grounds, (puts the collar around Zim's neck) it will explode. (The collar shrinks around Zim's neck. Dib is seen with an evil expression on his face)
Dib: You know Zim, when the nurse examines you, she'll notice that you don't have human organs. Then it's just a short step to a hospital and from there to an alien autopsy table and then you're just another segment on "Mysterious Mysteries"!
Zim: I'll be fine. I bet my squeedilyspooch on it.
Zim walks into the hallway and the many doors are shown: Biology, Chemistry, Taxidermy, Detention, Physics, Science, and Nurse. Zim heads towards Nurse but looks in biology room. He sees the health-biology teacher teaching a lesson and showing a guy with human organs. Zim looks back and forth from the teacher's anatomy chart to his own body. A worried expression appears on his face.
Hall Monitor: Hey. Where's your hall pass?
Zim: Say, you're full of organs, aren't you?
Hall Monitor: (looks at his torso) Why yes, yes I am.
Zim: And you wouldn't notice if you were, say missing a few?
Hall Monitor: (thinks for a second) Probably not.
Zim: (starts laughing evilly)
Hall Monitor starts laughing with Zim.
Zim reaches for his PAK and takes out something, an organ harvester.
Hall Monitor is screaming in pain and his shadow is shown. Hall Monitor walks around corner, looking pale and green and has his security glass on his eye as he walks. Zooms in on his belly button, goes pretty much all the way into his body and shows the exploding bomb collar hall pass, which is still beeping.
Ms. Bitters: And then the rats came for them. Thousands of them, dirty (shows Dib drawing a picture of Zim in a hospital cut open and a nurse finding out that he's an alien.) Dirty rats. (Dib looks over to Zim's empty desk) And these weren't the cuddly kind of rats (Dib breaks pencil) you get in today's sewers. (Dib raises his hand)
Dib: Ms. Bitters, I think a pencil is lodged in my brain? (Pencil is up his nose) Can I go to the nurse?
Ms. Bitters: How far in your brain?
Dib: (looks at his nose) Pretty far.
Ms. Bitters: Alright. Take the auxiliary hall pass.
Shows large radiator with the words "HALL PASS" spray-painted on it in neon green.
In the nurse's office, directional signs saying "Colds", "Flu", "Head Wounds", "Radiation Burns", and "Wedgie Burns" are posted on a wall next to a semicircle of different doors. Coughing is heard and then a scream is heard. A bored-looking secretary shakes a mooing can toy at her desk. A "moo" is heard. Dib drags the hall pass to her desk. Another cough is heard.
Dib: I'm looking for the pigeon-head kid.
Secretary: (shakes the can again, another "moo" sound) Nobody's come in with head pigeons, young man.
At the secretary's point of view. She shakes the can again, blocking Dib from sight. Another "moo" is heard. Dib shifts to his left to be seen.
The secretary shakes the can again, blocking DIb from view. Another "moo" is heard. Dib shifts back.
Dib: The green kid...
Secretary: Oh, the green child! (points to Hall Monitor, who is sitting in a chair across the room) He's right over there doubled over in pain.
Hall Monitor holds his stomach, pale green and shivering violently.
Hall Monitor: The cooing... (shivers and makes a gagging sound) The cooing!
Secretary: He's missing his liver. That's how some kids react to the cafeteria food... The lucky ones...
Another gagging sound is heard and the secretary goes back to shaking her mooing can; another "moo" is heard. Dib faces Hall Monitor and flips his ex-scope over his eyes. Two red lines meet in the lens of his goggles. Through his scope, Hall Monitor's skeleton and organs are visible with the words "Organ I.D." above him and some symbols on either side of his lens. Dib zooms in and the beeping collar is visible inside Hall Monitor. Hall Monitor gasps in pain. Dib zooms out and flips his ex-scope out of his eyes.
Dib: No! It's Zim! It has to be. He's stealing organs and replacing them with... stuff. He must be stopped!
Secretary: Don't forget the your pass!
The secretary shakes her mooing can, emitting another "moo" sound.
Dib noisily pushes his Hall Pass away. The camera shifts to a vent above the secretary's head. A close-up on a corner of the vent, where a screw is unscrewed and falls to the ground. From inside the vent from Zim's perspective, he lifts the vent cover away. The camera shows the secretary shaking her mooing can; it "moos" twice. A dome-like machine descends, stopping above the secretary's head. The secretary frowns and looks inquiringly at the can. Purple lightning zaps the secretary's head and a zap sound is heard. The secretary's brain is now in the dome. The secretary, her expression unchanged, drops the mooing can; it "moos" as it falls to the ground. The dome rises, then descends with a can of Poop soda. Another zap and the secretary's eyes go wide. She becomes pale and a phone rings. The secretary picks up the phone, opens her mouth to talk, and foamy dust spills from her mouth. The scene changes to Dib dragging his auxiliary hall pass down a hallway.
Dib: Must... warn... others... (looks around as the sound of pigeons cooing echoes through the vents) Zim? (more cooing) Zim? (to himself) Do not show fear. (stands taller) This is me without fear... and a sixty-two pound hall pass.
Dib continues struggling to drag the hall pass down the hall. Shift to Zim, who lifts the cover off a vent above Dib. Dib stops under the vent. The dome device lowers above Dib's head. The skool bell rings and children slam the door into Dib as they file out of a classroom, pushing him to the ground and bending the organ harvester dome sideways. A pig snorting is heard.
Dib: (reaching an arm up from the ground as kids walk past him) Hey! Wait! Your organs! In danger!
As Dib gets up, he hears a zapping sound. He turns and sees Spoon whose body is in the shape of Dib's radiator hall pass.
Spoon: I don't feel so good.
Spoon collapses onto his back.
Dib: The hall pass!
In the cafeteria, Dib peeks through the doorway. He sees Chunk green, whimpering, and rubbing his stomach. He falls over. Two kids (one of them is Rob) with trays of food walk into each other and collapse. A kid leans against a trashcan, his arm clutching his stomach in the background. Zoom in on the unknown kid who gurgles. Shift to the whole cafeteria, where all of the kids are pale green and slumped over on the tables.
Dib: Look at them...
Dib looks over at a sign that says "ToDAYS MEAL" to which a post-it note saying "MAYONNAISE AND CORN" is tacked.
Dib: ...And it's not even ketchup and rice day...
Shift over to Gaz, who is twisted sideways. A kid near her squeals like a pig.
Dib runs over to Gaz. Gaz is looking intently at a lit-up square in her side and poking herself in the side.
Gaz: Don't bother me, Dib. I'm in the zone.
She continues poking herself in the side. Sounds of lasers and explosions come from her. Dib looks confused. He puts on his ex-scope. He turns the knobs over his ears and two lines of light meet in the center of Dib's lens. From Dib's view, Gaz's skeleton and organs are visible. He zooms in on her side. There is a video game inside her and she is playing it. Dib gasps, then cringes. He looks up at another table, at which Melvin, Gretchen, and a third kid are seated. He zooms in on each of them: The unknown kid has a ruler instead of a spine, Gretchen has a remote control instead of a stomach, and Melvin has an alarm clock instead of a heart. He looks over at another table seating a girl and Carl. Carl has a carton of milk for a central organ and the girl has a cat inside her. Dib looks to the left and sees a mass of organs. A list scrolls by on the side of his lens reading "Brain, Stomach, Intestines, Colon, Spine, Tonsils, Heart, Appendix, Kidney, Liver". Dib gasps and flips his visor up. Zim is sitting at a table with a pigeon on his head, looking obese and drooling slightly. Dib runs over to him angrily.
Dib: That's it, Zim! This has to stop!
When Zim talks, organs are visible in his mouth. A snorting sound is heard in the background.
Zim: I'm afraid I don't know what you're talking about.
Dib: (gesturing at Zim) Look at you! You've gone too far! You're a hideous blob of stolen organs!
Zim: I've been working out.
Zim's cheeks bulge and he spits up a long, intestine-like organ. He gags and chokes for a bit, then smiles, relieved. He blanches, then sucks up the intestines like spaghetti and smiles. The intestines are still curled up in his mouth and he drools even more.
Dib: You think you can fool a trained medical professional?
Dib: I suppose you've got a heart in there...
Zim: Six of 'em.
Zim: Large or small?
Zim: In three different colors.
Dib: What about lungs?
Zim opens his mouth to speak, then stops, thinking. His eyes go wide. The pigeon on his head coos. Two arms come out of his Pak and go into a vent above him. They carry him up and out of sight.
Dib: You won't find lungs on my watch, Zim!
Dib looks around and sees Torque Smacky eating peas with one hand and lifting a weight with his other, looking healthy. Dib runs over to him.
Dib: You! You look like you still got all your organs!
Torque touches his own chest. Squishy sounds are heard.
Torque: Yeah. So?
Dib: You're in danger! Come with me!
Torque: (sighs) I have to go lift things...
Dib: D-um, then I'll come with you.
Torque lifts his hand weight while walking down the hallway while Dib runs behind him.
Dib: And he wants to destroy us all. Now I know you think I'm crazy, but you'll thank me... (yells) You'll all thank me!
Dib looks over and sees Carl half-carrying, half-dragging Matthew P. Mathers III down the hallway. Dib looks at them sadly, then hurries after Torque. He runs ahead of him and looks into classrooms and crevices as they walk.
Dib: Aliens are kind of a hobby of mine. Well, more like a way of life, really...
Torque: (as Dib searches) Man, you're creepin' me out...
Zoom in on a vent above Torque as he walks past where a Pak leg lifts the cover off.
Dib: I have vague memories of being taken on board an alien ship as a baby.
Behind Dib, a Pak leg reaches out and grabs Torque, lifting him away. Dib continues walking and talking, oblivious.
Dib: And I'm not sure, but I think they were doing tests on me... Trying to create some kind of genius super-baby perhaps...
Something lights up behind Dib and the sound of something being powered up is heard. Dib turns and sees that the light is coming from a room. He runs to it. The light shuts off. Dib peers in the room.
Dib: Torque? (he slowly enters the room) Torque Smackey, is that you?
Dib turns on the light switch and walks through what seems to be a science closet. Jars with eyeballs and other unidentified substances are on a shelf by the wall. There are statues of birds of prey and a human and many boxes. Dib looks at some jars with things floating in them. He walks past a human skeleton, sees it, flinches, and realizes it is a model of a skeleton for display in schools. He continues walking.
Dib: Come on, man. Talk to me... Let me know you're still here!
Dib walks past a screen that shows his skeleton and organs. After Dib passes, a grinning Zim descends by two PAK legs, his body stuffed with organs visible through the x-ray screen. Once he reaches the ground, all four Pak legs launch him after Dib, feathers from his pigeon falling behind. Dib keeps wandering around the room. He hears Torque's hand weight fall behind him. He looks at it, gasps, and looks up. Cooing comes from an open vent.
Dib: (screaming in grief) TORQUE SMACKEEEE!
A PAK leg reaches over and turns out the light switch. Dib looks over. Zoom in on a Woolly Mammoth statue. Dib looks the other way. Zoom in on a statue of five birds of prey on a perch. Close up on Dib's face.
Quick shots of the Mammoth, the open vent, the birds of prey, and some toxic waste barrels. Dib crashes through some toxic waste barrels and backs up slowly. He hits a bird of prey statue and feathers fall. He backs up and trips over a box of papers. He runs and exits the closet. When the door opens, the light is cast on a grinning Zim, and then a shadow is cast. The light is cast on the same spot again but Zim is gone. Dib runs down the hallway and ceiling tiles fall off behind him (it is assumed that Zim is following in the air vent). Ceiling tiles fall off faster and faster as Zim gains on Dib. Dib looks back as he reaches a wall. He turns and runs the other way, sliding under a rail to another landing. Dib looks up and cooing is heard as the camera zooms in on the ceiling, then a vent, then a ceiling vent next to it, then a third vent. Feathers come out of the third vent. Dib covers his ears, then runs to a door marked "STAFF ONLY". He goes inside and as the door closes, the camera shows another sign that says "BOILER ROOM". Dib runs down a spiral staircase, steam flooding the air next to him. He runs over a wire bridge and under a machine that spits out more steam. Dib keeps running down the bridge. Through the fog, obese Zim slowly descends, blocking Dib's path. Dib stops.
Zim raises himself higher with the PAK legs, grins widely, then raises his organ harvester. There is a white flash and Dib is still screaming. The screen goes black and Dib stops screaming.
In the nurse's office, Zim sits next to Dib. Both have thermometers in their mouths. Zim is still drooling and there is still a pigeon on his head. A sign behind them has a red cross and reads "WE NEED YOUR BLOOD". Dib opens his mouth and emits a mooing sound.
Ms. Bitters: (pointing at Zim) That one has head pigeons. The other one is just annoying. Fix it.
The secretary makes a gurgling, moaning sound and foam spills from her mouth.
Dib: (weakly) Your stupid plan won't work, Zim. (inhales and moos) You'll never pull this off. (exhales and moos again)
Zim: (mouth full of organs) You shpeak craziness, Earth boy! More organsh meansh more human. It will work...
A nurse walks up to Zim and Dib. She takes the thermometer out of Zim's mouth and shoos the pigeon off his head.
Nurse: (looks at the thermometer) There! Why, you're one of the healthiest little children I've ever seen! (puts her hands on her knees) And such plentiful organs! (Zim smiles triumphantly, swings his legs, and looks at Dib)
Nurse: (walks over to Dib) And what's the matter with you, young man?
The nurse takes the thermometer out of Dib's mouth. Dib opens his mouth. From a view at the back of his throat, we see the nurse grab his tongue and Dib close his mouth. She uses a stethoscope to listen to Dib's breathing. Dib inhales, then moos. The nurse blanches, then screams and points at Dib.
Nurse: It isn't human! It's horrible!
Dib: (points weakly at Zim) But, he-
A crowd of people holding cameras and microphones crowd around Dib and take pictures. A newspaper spins to center screen, the top story reading "HIDEOUS MOOING CYBORG BOY FOUND!" with a picture of Dib with hooves and a cow's face.