At Destroido, Kelsepsian is walking out of the building to his car when he gets a phone call.
Kelsepsian: On my way home now, darling.
???: You did not heed my warning.
Kelsepsian: Honey, what's wrong with your voice? It's so deep. Wait a minute. Is this that nut again?
???: I told you if you did quit your job at Destroido and leave forever something terrible will happen to you.
Kelsepsian: And I told you, I don't appreciate prank calls! My sister-in-law is a paralegal, and if this keeps up, I'm suing you! Go suck a lemon!
He hangs up.
Kelsepsian: Oh, boy! The nerve of some people!
He drives off and stops at a stop light when a cicada lands on his windshield.
Kelsepsian: Ew. It's one of those cicada things. I hate those bugs.
He uses his wiper to hit it off. The light turns green and drives as more and more cicada land on the car. Eventually they make it into the car as a horde of cicadas swarms the car as more makes it inside the car.
Kelsepsian: What's going on? Hey. Go away! Come on! Shoo. Shoo. I give up!
Kelsepsian swerves his car as the cicada attacks him and he drives his car off a cliff, crashing the car. The cicadas come together and form a massive cicada.
???: I warned you.
The next morning the gang was in class with Dr. Yantz who is teaching the class.
Dr. Yantz: The cicada, the most perfect insect in a decidedly imperfect world.
Dr. Yantz kisses the cicada.
Y/N: Okay, ew.
Fred: Did he just kiss a bug?
Daphne: He may be cute, but he's not the one I have my eyes on.
Daphne and Y/N look at each other and smile.
Dr. Yantz: The cicada's life cycle is fascinating. As grub, they burrow into the ground where they spend the next seventeen years.
Scooby was eating chips and tapped Velma's shoulder.
Scooby: Psst! Want one?
Velma: Not from you I don't.
Scooby: Oh. Can we just be friends?
Velma: Ask me in seventeen years.
Dr. Yantz: Changes in our ecosystem, though could wipe out the precious cicada which is why we need to keep watch on companies who pollute nature. Isn't that right, Shaggy and Scooby?
Both Scooby and Shaggy were not paying attention as their were eating chips.
Scooby: Huh?
Shaggy: Pardon?
Dr. Yantz: Are you aware that Grandma Moonbeam's Nature Silvers are manufactured by Destroido? And every bite you take supports the biggest polluter in Crystal Cove?
Shaggy: No. But they're, like, super good.
Scooby: Yeah. Want one?
Dr. Yantz: I don't even know why I let you take this class.
The bell rings as everyone leaves class.
Fred: That guy's a total nut.
Y/N and Daphne were walking together as Daphne looked at Y/N.
Daphne: Y/N?
Y/N: Yeah?
Daphne: I was wondering if you would like to-
Shaggy was eating his chips when he pulled out a paper from his mouth.
Shaggy: Ooh! It's a note from Mr. E. Must have been in the bag of my Nature Silvers. He says there's a mystery waiting for us at the hospital. There's been some sort of weird accident.
Fred: What kind of accident?
Shaggy spits out another note.
Shaggy: He says we'll find out when we get there.
At the hospital there were police cars.
Velma: Looks like Mr. E was right. Something's up. That's Sheriff Stone's car.
Shaggy: Like maybe we can stop by the cafeteria when we're done and get some of that delicious hospital gelatin.
Scooby: Yeah, with saltines and applesauce.
Shaggy: In gelatin.
They enter as Kelsepsian is getting the bugs pulled out of his nose.
Nurse: Steady now.
He gets the bug pulled out.
Nurse: There.
The cicada flies off as Sheriff Stone gets scared by the bug. Mayor Jones is on the phone.
Sheriff Stone: Ew. It's on me. Get it off. Get it off. Get it off. Get it off!
Mayor Jones: Calm down. It's just a bug.
Mayor Jones hits the bug away.
Sheriff Stone: Thank you.
Fred: Dad?
Mayor Jones: Oh, no.
Fred: Can we help with anything?
Mayor Jones: No. Go away.
Velma: Who's the patient?
Mayor Jones: An employee of Destroido. Go away.
Shaggy: Like, what happened to him?
Mayor Jones: It's classified. Go away.
Sheriff Stone: It was this awful creature made of thousands and thousands of cicada bugs. They got in his hair, in his nose, all over him! And... Ew. Ew. Ew. Gross!
Mayor Jones: What are you three-years-old? Alright. Fine. Yes. A bug creature, okay? And I'm not gonna let a golden opportunity like this go to waste. I already talked with the city council. We're gonna have a cicada bug creature festival this weekend. The crowds will be huge. And if you have any human decency left in your hearts you will not get involved.
Mayor Jones and Sheriff Stone walk away.
Fred: Sorry, dad, but we can't do that.
A cicada sees them. Night came and Hugh Dederdee was taking a shower when he got a phone call. He turns off the shower and answers it.
Hugh: Hello?
???: You did not heed my warning.
It was the mysterious caller.
Hugh: You again. I'm taking a shower. Stop calling me.
???: I told you if you did quit your job at Destroido and leave town forever something terrible will happen to you.
Hugh: Blah, blah, blah. Leave me alone.
He hangs up and goes back to taking a shower, but no water came out. He checked it when a cicada came out.
Hugh: What is that? A bug?
That's when swarms of cicadas came out and attacked him. The next morning Scooby was watching a commercial while he and the gang were in the hospital waiting room.
Commerical: From fields and rivers come Nature Slivers, fish oil, flax, and wheat. Grandma Moonbeam cooks in her kitchen to give you good things to eat. Nature Slivers! When you want fish oil, flax, and wheat in one crunchy bite Nature Slivers. A division of Destroido.
Scooby: Ohh. I want to bite some Nature Slivers.
Shaggy: Like me too.
Fred comes over to them.
Fred: Okay, gang. I got it. Room 24-B.
They went to the room where Hugh was staying, and Grandma Moonbeam was there.
Grandma Moonbeam: There, there. Poor dear. Such and ordeal.
Y/N: Mr. Dederdee? Can we ask you a few questions?
Velma: We heard about your bug attack last night.
Hugh: Come on in. I'm not going anywhere.
Grandma Moonbeam: Well, I should go. Feel better, dear.
Shaggy and Scooby: Grandma Moonbeam?
Shaggy: We're, like, your biggest fans.
Scooby: Nature Silvers. Yummy.
Grandma Moonbeam: Well, now, isn't that nice? After I sold my company to Destroido Hugh here has been instrumental in making them so popular among young people.
Fred: You work at Destroido too?
Hugh: Mm-hmm.
Velma: Just like the other victim.
Grandma Moonbeam: Well, I'll leave you all to talk.
She leaves.
Fred: Mr. Dederdee, do you have any idea why you were attacked?
Hugh: Not really. I got a call a couple weeks ago. Some deep-voiced creepy guy said if I didn't quit my job at Destroido something terrible would happen to me. I never thought it will be...
The heart monitor beeps faster.
Hugh: Disgusting bugs... Bugs, bugs all over me! Bug! Buzzing bugs! All over me! Bugs! Bugs! Bugs!
He screams as the gang leaves.
Daphne: Thanks again, Mr. Dederdee.
PA: Code Blue. Crash cart in room 613.
Fred: Good question-and-answer session, eh, gang.
Y/N hears the flatline.
Y/N: It... could have gone better.
They enter the elevator.
Fred: Uh, hit the lobby, will you, Shag?
Shaggy clicks lobby and they go down to the basement.
Velma: Nice one, dog boy. You pressed the wrong button. This is the basement.
Shaggy: No, I didn't. Like, see? Lobby.
Y/N tries to click lobby but nothing.
Scooby: Hmm. Must be broken.
Fred turns on the lights and it short circuits and the elevator closes behind them.
Y/N: Guys, do you hear that?
They all hear sounds coming from the pipes as the vent opens and they are swarmed with cicadas swarm them as a massive cicada approach them.
???: Cease your useless investigations or something terrible will happen to you tomorrow night. Heed my warning. Heed it. Heed!
The cicadas flee into the vent and the elevator opens. They get into the Mystery Machine and drive off.
Velma: There has to be some reason the victims all work for Destroido.
Scooby spits out a cicada and flies out.
Shaggy: Like, maybe who's ever behind it doesn't like the company.
Daphne: But who could train thousands of bugs to attack like that?
Fred makes a hard brake.
Fred: The same person who kisses them!
Daphne: What?
Fred: Dr. Yantz. It all fits. Remember what he said in class about Destroido being one of the biggest polluters in Crystal Cove? He hates that company.
Y/N: You sure?
Velma: He is an expert on cicadas.
Y/N: Fred might be on to something. Let's go to school.
They drive to their school and see Dr. Yantz sitting down.
Scooby: Uh, is he, like, in there?
Fred: Yeah. Let's go.
They enter as Dr. Yantz sings with an instrument.
Fred: The jig is up, Dr. Yantz. Watch out for his weapon, gang. No doubt he's got the cicada under some of brain control.
Dr. Yantz: I was putting them to sleep. It's their bedtime.
Shaggy: Huh! That's a good one, right, Scooby-Doo? Huh?
Scooby is sleeping.
Dr. Yantz: What is going on here?
Velma: You've been using cicada bugs to attack employees at Destroido.
Dr. Yantz: Are you insane? I'm calling the police.
The police arrived as the gang were all talking at once.
Mayor Jones: Quiet. Now, one at a time.
Y/N: Dr. Yantz is the cicada creature, Mayor.
Sheriff Stone: You are? Ew!
Mayor Jones: Let's not jump to conclusions. But if you are the cicada creature would you mind showing up at the cicada festival tomorrow? It would be a big help.
Dr. Yantz: I'm not the cicada creature.
Mayor Jones: Of course, you're not. Show up around 6:00. I'll have a photographer there.
Dr. Yantz: If you don't get these kids out of here right now I'm pressing charges.
They leave as Dr. Yantz shuts the door.
Fred: But dad, we have to find out who the creature is, and fast.
Mayor Jones: Why, so you can ruin everything?
Daphne: No, because it said it was going to attack us tomorrow night!
Mayor Jones: Tomorrow night? That's wonderful!
Gang: What?
Mayor Jones: I mean, terrible. Awful. Fortunately, I know what to do. Come to cicada festival tomorrow night so we can, protect you 6 o'clock. Let's hire a photographer. This is perfect. Well, now. Who wants to go out for cheesecake?
They all look at each other as Y/N slowly raises his hand. The next day, Ed Machine was playing golf as a friend drives up.
Ed's Friend: Ed, come on. Let's go back to the clubhouse. It's getting dark.
Ed: Forget it. I'm having the best game of my life.
Ed's friend drives off and before he can hit the golf ball, he gets a phone call. He answers.
???: You did not heed my warning!
It was the mysterious caller again.
???: I told you that if you-
Ed: Yeah, yeah. Quit my job at Destroido, or something terrible would happen to me. Listen, you, I'm the CEO of the company and I'm not going anywhere. Now get lost.
He hangs up and hits the golf ball and makes it into the hole.
Ed: That's the way to do it.
The ball comes out of the hole.
Ed: Huh?
The flagpole falls.
Ed: What?
He looks in the hole and the cicadas attack him. At K-Ghoul, Velma was reading the newspaper.
Velma: Looks like that cicada thing struck again last night.
Shaggy: And, like we're next. Tonight!
Fred: Hey, don't worry. I've got it all figured out. I was up all night building a trap and believe me, we'll catch it.
Scooby: Or die trying.
At the cicada festival Fred finishes setting up the trap.
Fred: Okay, remember, we need to lure the creature to the mystery machine here, where the trap is.
Scooby: How do we do that?
Y/N: Simple. The six of us are bait.
Shaggy: I was afraid you'd say that.
Inside the festival everyone is there enjoying the night eating, taking pictures with mascots and much more. Y/N and Daphne were together.
Y/N: Daphne, what were you trying to say at school the other day?
Daphne was blushing.
Daphne: Well, I was wondering if you would... want to... go out with me?
Y/N: Like a date?
Daphne: I mean-
Y/N: I'd love too.
At this point Y/N and Daphne were both blushing, and they lean in when Fred yells.
Fred: Hey, gang I found dad.
Mayor Jones: Where have you been? That thing could have attacked you and we wouldn't have had any pictures.
Fred: Gosh, dad. You really care! Aw thanks.
He hugs his dad.
Fred: Don't worry. We're just walking around so the creature knows we're here.
Mayor Jones: Oh. Good idea. Yeah. And if that thing attacks, run back here so we can get pictures.
Shaggy then sees Dr. Yantz go inside the House of Spooky Things.
Shaggy: Like, dudes, I just saw Dr. Yantz go in the House of Spooky Things!
Fred: Just the break we need. Let's follow him.
The gang enters and gets scared by a bunch of cardboard monsters.
Shaggy: Like, that's not very spooky.
Scooby: Not spooky.
Y/N: They could have done better.
A clown's head comes out.
Shaggy: Nope. Not spooky.
Scooby: Not spooky at all.
Y/N: This is surprisingly sad.
A silhouette of a witch is shown.
Shaggy: Like, this is definitely not spooky.
Y/N: They are not even trying.
Suddenly two large doors blocked their way.
Shaggy: Now, this is spooky.
Y/N: Okay, now I'm scared.
They then hear buzzing.
Velma: What's that noise?
A horde of cicadas appear behind them.
???: You will pay the price!
Fred breaks open the wall as they run past Dr. Yantz.
Shaggy: Like, I don't think it's Dr. Yantz!
Velma: Really? You think?
The massive cicada creature comes out and chases the gang.
Fred: Lead it back to the mystery machine.
They run to the mystery machine as one by one they are covered by the cicadas. Fred presses a button, and the van opens, and a vacuum activates and sucks up all the cicadas. Scooby grabs the vacuum and points it at the massive cicada, and it screeches as it shrinks to a person wearing a bee suit.
Fred: Now. Get him!
Shaggy takes off the bee hat revealing Grandma Moonbeam.
Gang: Grandma Moonbeam?
Mayor Jones, Sheriff Stone, and photographer come running towards them.
Mayor Jones: Did we miss it? Where are the bugs?
Fred: You're the cicada creature? But why?
Grandma Moonbeam: Isn't it obvious? I wanted to shut down Destroido. I found out they added a secret ingredient to make nature slivers more tasty: Landfill waste! I demanded that they return to my original healthy recipe, but they refused, and because they owned it, there was nothing I could do. I vowed to get even. I saw a Norwegian documentary about a researcher using sound waves to control penguins' movements. I decided to adapt the idea for my revenge. Since I didn't have any penguins, I used cicadas. And I would have succeeded, too, if it hadn't been for you meddling young people.
Sheriff Stone: Well, now, it's the big house for you, grandma. Let's go.
She is taken away.
Mayor Jones: Why can't anything in this town ever turn out to be real?
Fred: Glad we could help, dad.
Velma: Well, another mystery successfully solved.
Shaggy: I'll say, like, who's up for a trip at the Clam Cabin? It's all-you-can-eat krill night.
Scooby: Krill? Oh, yum.
Daphne: Sorry, gang, but Y/N and I are gonna have to pass. We've got a date.
Y/N and Daphne smile as they go to Y/N's home a watch a movie with a blanket covering them. Meanwhile, inside the basement Y/N's siblings are there.
S/N: Just five more and we can make everything right again.
B/N looks at a drawing of a completed disc.
B/N: We can be a happy family again...
The two looks at the drawing.