The episode opens up with the Turtles prowling the streets in the Shellraiser, with Mikey (with something covering his head) sighing, while spinning around on his chair. Then, he takes the object off and grumbles, "Another day, another Kraang hunt." While Raph is laser-focused on his weapons targeting screen, Mikey quickly comes up behind him and tells him to fire the weapons, to which he refuses. Mikey says that if he were in charge of the weapons, he would always be firing them and goes on to exclaim how he would be destroying every single thing that they pass. Leo says that's precisely why he's not in charge of the weapons, and tells him to get back to his station and tell him where to go. Mikey obeys and looks at the map, stating that they "should turn right...3 blocks ago", followed by the others letting out a long, exasperated sigh. The boys finally reach their location that Donnie believes to be a hidden Kraang laboratory that they've apparently been looking into and studying. Raph immediately wants to trash the place once they get in, but Leo stops him on account of wanting to follow their own plan and keep it a simple recon mission; Go in there, find out what the Kraang's plot is, and then trash the place if necessary. They carefully walk in, to find the place a complete wreck with countless pieces of the Kraang's robot parts dispersed on the floor. Raph immediatly believes that somebody must've beaten them to it, but Leo thinks that one of their mutagenic experiments successfully escaped from them and gone rogue. When some diagrams come into view, Donnie concludes that the Kraang must've been doing experiments on arthropods. While the Turtles investigate further, Mikey goofs off and spins on a desk chair while Donnie states that their equipment is still in good condition, and joyfully checks out a centrifuge, to which Raph instructs Leo to "put him out of his misery if he ever gets that hyped about a centrifuge. When Mikey picks up a Kraang-robot head, something seems to catch his eye and he asks Donnie how big some arthropods would normally be. Donnie replies that bees would be about 4mm, and wasps would typically be 6mm. "Then what the heck is that?!?", he exclaims, pointing to the nearby rafters. Suddenly, the mutant that escaped the Kraang's containment emerges from an opening in the ceiling; a giant wasp.
As the wasp begins to attack, the Turtles dodge it - all except for Raph. He is pinned down, until Donnie uses his bo staff to quickly knock it away. Then, it goes after Don, but Raph once again attacks from behind, but is smashed into the ceiling instead, then dropped onto the floor. Leo then hits the wasp with his two katanas and it smacks into the wall, which buys the turtles the time they need to hide. While it searches for them, they try to devise an attack plan. Mikey suggests that he uses his kusarigama chain to catch it off guard, but Leo denies it, explaining that the insect is simply too strong for such an idea. Instead, Leo suggests Mikey distracts the monster so Leo, Raph, and Donnie can ambush it. Mikey asks why they never go along with his plans, and Leo says that it's because they are "his plans", and Mikey begrudgingly proceeds. Mikey succeeds in getting the wasp's attention, but then it comes closer and starts chasing him around the room. As the turtles watch, Raph is intrigued that Mikey has apparently turned "running away screaming" into an art form. Mikey dodges one close call after the next, until he eventually becomes so tired that he trips and falls down. The gargantuan wasp tries to sting him, narrowly missing, and the others then proceed with ambushing the wasp, but they miss as a result of Mikey not closely following the plan and using his kusarigama. Mikey knocks both the other Turtles and the wasp down, but it then it starts frantically flying around the room, taking Mikey along with it. Raph and Donnie then get smacked into the wall once again. Whilst Leo is distracted, he swiftly pulls out one katana, but the wasp sneaks up behind him. As a result of the monster's speed, Leo can't get out of the way in time and he is promptly stung. The wasp continues to fly towards the others before dropping dead to the floor on its back. Mikey says that he tired it out, but Donnie corrects him, explaining that the wasp died due to the loss of it's stinger...into Leo, revealing the enormous stinger lodged into his left bicep. "Thanks a lot, Mikey!!", he says as Raph gags at the rather horrid sight. Donnie then harshly removes the stinger, resulting in a small yelp from Leo. Donnie then asks Leo if he's alright, with Leo replying that he's sore, but believes he will be fine, finishing the sentence with awkward twitching. Donnie examines the stinger and becomes intrigued by the wasp's mutation, stating that mutants like these are usually anthropomorphic. He has never seen mutagen create simple giants like that wasp before. Leo then wanders off and unveils an egg under a newspaper. Mikey prepares to break it, but Leo quickly intervenes, and decides to take it back to the lair "and let Donnie analyze it". Raph sarcastically remarks is reluctant to take the mutant wasp egg to their home, so Leo justifies things by saying that they can't just leave it in the city and that he will keep an eye on it. Mikey offers to carry it, but out of nowhere Leo harshly bats him away. This confuses Raph even furthermore since unprovoked ragebites are normally his shtick. Leo says that it could be extremely fragile and he carries it out the door himself.
They reach home and Leo comes out of the Shellraiser, carrying the egg, with Raph declaring that he has a very bad feeling about keeping it in the lair. He places the egg on a beanbag in Donnie's lab, and Donnie is about to dissect it, but Leo yells at him and shoos him away, claiming that they must "learn how it develops". Donnie agrees to "just keep staring at it" in that case. Pointing strait at the door, he orders "From over there". Donnie takes a wide step to the right and nervously grins at Leo. But Leo gives him the Black Bar Stare, which prompts him to follow Leo's direct order. And so, Donnie decides that he needs to do "something" in another room and asks if Raph and Mikey would join him. In the Kitchen, Raph, Donnie, and Mikey are talking in the kitchen about Leo acting totally weird. Raph agrees, saying that he's virtually obsessed with the egg. Mikey suggests asking Splinter what to do, but Donnie says that he is busy training April. The boys agree that they're main objective is destroying the egg before it hatches, but have to find a way to get past Leo. So Mikey suggests they try and make Leo come to them, but Leo overhears all of this from Donnie's lab. Just then, his voice begins flocculating and he experiences a severe headache, followed by his eyes twitching. Mikey comes in with a box of fresh Pizza claiming to be Leo's favorite; jellybean, jalapeño, and anchovy. Donnie quietly tells Mikey that that's his favorite, but Mikey just instructs to go with it since he doesn't actually know if Leo has a favorite. The brothers go up to Leo, exclaiming how tasty it is, but he completely ignores them. For their next attempt, they turn on an episode of Space Heroes reflecting their current situation; Captain Ryan falling under the control of a "deadly Hypnotica" that brainwashes him into believing it's his fiancé. That doesn't work either. And so, Mikey gets ahold of Leo's signed issue #1 comic-book of Space Heroes that he keeps wrapped in plastic for his next plan, which is tricking Leo into thinking that he's using it as toilet paper. However, he strikes out a third time. Donnie is very surprised at Leo since he didn't even flinch. Losing his patience, Raph says that he will destroy the egg that night by himself. Later, Raph sneaks into Donnie's lab and prepares to stab right into the egg with his sai. Leo appears and blocks the attack. Raph asks Leo why he's protecting the egg. Not saying a work, Leo reveals his pupils have completely grazed over his eyes, and takes Raph to the ground. He tries to speculate that the hatchling will try to eat them if it hatches, but Leo arms himself and moistly hisses. Raph declares that "this freakshow ends now", and charges at his brother.
Leo and Raph fight, and Raph manages to hit one of Leo's katanas, sending it flying into the ceiling. At that moment while Leo's arm is aching from his sting wound, Raph tells him that he's not himself and urges him to let him help him. Leo roars at him and starts going hard on him. Raph struggles to hold his ground, only barely managing to shoo him off. But Leo recovers quicker than he anticipates and lunges at Raph as he stands up. In the heat of that struggle, Raph stands up and notices a black bite mark on his right bicep. Raph yells at Leo that he bit him, with Leo's only response being a sickening grin. The next morning, Donnie and Mikey wake up and wonder where Raph is, with Mikey remembering that he went for the egg last night. They then peer inside Donnie's lab to see both boys. They see Raph and Leo standing stalwartly towards the egg, guarding it with their lives. Donnie asks Raph what he's up to, but Mikey tells him that "he's gone all "Leo who's not Leo" on us". Donnie begins looking more close and sees the bite mark on Raph's arm. As Donnie concludes that leo bit him, Leo and Raph slowly pull out their weapons and charge at Mikey and Donnie. They manage to escape and lock Leo and Raph in the lab with Mikey's kusarigama. But Donnie realizes the garage door is still open, and Mikey races to close it. As he tries to get the door unstuck, Leo and Raph see him and loudly hiss at him. Mikey panics to force the door down as Leo and Raph race for the exit, but Mikey manages to secure it. Back in the kitchen, Mikey and Donnie do some research on the wasp that they encountered the other night. Donnie finds an article describing a parasitic wasp. A wasp that infects animals with a virus that brainwashes its victims into guarding its egg. As Leo becomes nervous at the sound of Leo and Raph banging at the door, him and Donnie conclude that it's the same wasp that stung Leo in the lab, infecting him with the virus. Then Leo bit Raph and passed the virus to him. Donnie scrolls further down the article to see what happens when the egg hatches. Instead of the virus wearing off, the newborn wasp devours its guardian alive. Mikey horrifically asks Donnie what they should do. Donnie says that he can administer some type of antibody into their system. All he needs is a sample of the virus from the egg itself. Suddenly, Leo and Raph manage to break the door down and escape from the lab. They start chasing Donnie and Mikey around the lair. Leo jumps on Donnie and Raph on Mikey, but Mikey is able to use his nunchucks to throw Raph over his himself and into the nearby sewer water. Mikey then subdues Leo, and they see that Raph has made off with the egg. As the boys barricade themselves in Donnie's lab, Leo then pretends to come back to normal, asking Mikey to untie him, but Donnie stops him. Seeing through the deception, he tells Mikey to look at Leo's eyes. Leo begins to squirm as he fights to break free from the chains, and he monologues in a fluctuated voice; "It is useless to resist. It is only a matter of time before the egg bursts! and the hatchling will feed on us all!". Donnie slaps Leo into silence and takes a sample of his blood, claiming that that should be enough to help him create a cure for the virus. Mikey then discovers that Donnie now has a black bite mark on the left side of his lower neck. Donnie concludes that he must've been bitten during the fight. Now, he's infected too.
While working on the antidote, Donnie begins to stress at his time running out. And so, he instructs Mikey to knock him out if he turns so that he can finish the antidote himself. As Donnie gives Mikey the last of the instructions for the formula, he then starts to change and Mikey tries to strike him down. Now fully turned, Donnie blocks the attack and he manages to bite Mikey in the forearm. It's at that moment that Mikey strikes his knock-out blow to Donnie. With Mikey now infected as well, he tries to work on the antidote and remember what Donnie said, but he then seemingly falls unconscious. Back in the Lair, Leo and Donnie come to Raph, who is guarding the egg at the top of the spiral stares in the living room. He then asks about Mikey, and Donnie says that Mikey has been successfully infected. Raph jumps down and the boys surround the egg. Mikey promptly joins them, and the egg curdles, signifying that it is about to hatch. As Leo, Donnie, and Raph drop their weapons and exclaim how glorious it is going to be, Mikey suddenly plunges the syringe into all of their necks, administering the antidote just in time. They begin wondering how he managed to survive, since Donnie was sure that he turned him. He said that when Donnie bit him, he was all dizzy and fainted about 19 times, according to his calculations. He then started spinning around a chair, hurting his head to resist the virus's grip on his mind so that he could remember what Donnie said. And thus, he put his powers of recall to work. While the other Turtles return to normal, they are in awe to hear that Mikey has done something smart by finishing the antidote himself. As Mikey brags, he then mentions that the formula may also cause temporary drowsiness. At that moment, Donnie, Raph, and Leo pass out at the same time. The egg then hatches, and to Mikey's surprise, 3 giant wasps have emerged. When they are all about to consume the other three Turtles, Mikey swats the wasps off with his skateboard, and he runs to the Shellraiser for cover. The other Turtles soon awaken and come fight the 3 wasps, until they are all subsequently surrounded. Then, Mikey, still inside the Shellraiser, uses the compressed garbage cannon to splatter all 3 of the monsters to gold-colored ooze. Mikey comes out of the Shellraiser and announces his victory and saving his brothers lives a second time. With the threat eradicated once and for all, Leo and Raph are mopping up the liquid wasp guts while Donnie patches up the stinger holes in the Shellraiser door. When Donnie refuses to "pizza" him, he tries to guilt trip him by recapping his recent victory and saving his brothers. Leo agrees that he saved their lives, but that doesn't excuse him for using his prized comic as toilet paper, albeit obviously not knowing it was a trick. Leo then starts furiously chasing after him while Donnie resumes patching up the Shellraiser. Raph watches in smug glee as Leo takes his mop on Mikey, ending the episode with the comic shot of Mikey begging for mercy.
This episode aired early in the UK on June 15th, 2013.
Parasitica is an order of parasitoid wasps.
However, given how it's the title of the episode, it's most likely the name Mikey has christened the wasp monster.
Donnie indicated that the parasitic wasp died because it lost its stinger, but that actually doesn't happen to a real parasitic wasp.
It also shares similarities with the 1987 series episode "Big Bug Blunder" where Krang accidentally creates a mutagen that enlarges arthropods.
Parasitic wasps don't brainwash their hosts to guard the egg. Rather, they implant the egg inside a host, which hatches, feeds on the host's internal organs, pupates, and kills the host, either escaping the now empty body or remaining in it.
The shape-shifting alien disguised as a woman shown in Space Heroes is a parody of the Salt Vampire from the first episode of Star Trek.
When Mikey tries to lure Leo away with his Space Heroes comic book, the publisher label in the top left corner shows "Lock &" over a key. This is a reference to the comic book series "Locke & Key", which is published by IDW, who also publish the TMNT comics.
This is the first episode to have a plot involving the turtles dealing with a conundrum of their own instead of any actual villains being involved.
Crankshaw implies that the reason Leo is infatuated with egg because he is under the control of a parasitic wasp.
When Leo and Raph pull out their weapons and they turn around to fight Mikey and Donnie, the front of Raphael's belt is missing.
"Michelangelo: "Hey, Raph! Fire the weapons!" Raphael: "I don't think so." Michelangelo: "See, that's your problem. If I was in charge of weapons, I'd be firing at things all the time! That mailbox, blam. That newsstand, boom. That port-a-potty, splat." Leonardo: "And that's why your not in charge of the weapons. Now get back to your station and tell me which way to go." Michelangelo: (Mikey sits back down and looks at the map of the city.) "Hmm. Okay. Uh, you should turn right... three blocks ago." (Raph, Donnie and Leo groan.)"
"Michelangelo: (noticed something) "Hmm? Hey, Donnie, how big do you think one of those arthropods might be?" Donatello: "Well, a bee is about 4 millimeters, and a wasp would be 6." Michelangelo: "THEN WHAT THE HECK IS THAT?!" (the Turtles look above to see an oversized parasitic wasp)"
"(Mikey is running and screaming around the room with the wasp chasing him, while the others watch.) Raphael: "He's really turned running away screaming into an art form." Donatello: "Well, at least he's good at something, right?" (Mikey trips and falls to the floor.) Donatello: "Good-ish.""
"Leonardo: (after the wasp stings him) "OW!" (the wasp approaches Donnie, Mikey and Raph as it falls dead on the ground with its legs curled up, while it slightly twitches before it finally stays motionless)Michelangelo: "See? My plan worked! I tired it out!
Donatello: "You didn't tire it out. The wasp died because it lost its stinger." (the wasp's abdomen is shown without its stinger with some slime coming out, then Leo arrives with his left arm pierced with the stinger that has a small brain) Leonardo: "Yeah, in me! Thanks a lot, Mikey!" (all of the Turtles look surprised to see his swollen mark with the stinger stuck on it.) Michelangelo: "Heh, sorry, dude." Donatello: "Let me see that." (removes the stinger) Leonardo: "OW!" Donatello: "Are you okay?" Leonardo: "Pretty sore, but I-I-I think I'll be..." (his eyes twitch) "...fine." Donatello: "Mutations are generally anthropomorphic. I've never seen mutagen create giants like this before." Raphael: (sarcastically) "Yeah, real fascinating, Donnie.""
"Leonardo: "Whoa! Look!" (removes some newspaper to see a large wasp egg)Donatello: "It's some kind of... egg." Michelangelo: "Stand back. I'll handle this." Raphael: "I'm betting on the egg." (Mikey takes out his nunchucks to smash the egg, until Leo stops him)Leonardo: "WAIT! We're not hurting it. We came here to find out what the Kraang are up to, and this egg is our only clue. We should take it back to the lab and let Donnie analyze it." Raphael: (angrily and sarcastically) "Great idea! Let's take the mutant wasp egg into our home where we live! What's the worse that can happen?!" Leonardo: "It's not safe leaving us around. It'll be fine, I'll just keep an eye on it." Michelangelo: "I'll get it." Leonardo: "HANDS OFF!!" (Mikey yelps, making him and the others startled with confusion) Raphael: "Dude, are you alright? 'Cause unmotivated bursts of anger are kind of my thing." Leonardo: "It's just that the egg could be fragile." (picks up the egg) "Michelangelo cannot be trusted with it. I'm carrying it myself." Michelangelo: "I'm beginning he's liking that egg more than me." Raphael: "Well, the egg talks less than you, so there's that.""
"Michelangelo: "Who want's pizza? Leo's favorite! Jellybean, anchovy and jalapeño!" Donatello: "Isn't that your favorite?" Michelangelo: "Just go with it." (all three arrive in the lab, and they start eating their slices) All: "Mmm!" Michelangelo: "Leo." (Leo doesn't do anything else, making the others disappointed)"
"Raphael: (trying to get Leo's attention) "Oh, boy! That not and all stupid Space Heroes show is on!" Captain Ryan: "Gentlemen, I finally found the woman I am going to marry. Say hello to the future Mrs. Captain Ryan." (his 'bride' reveals herself to be a beautiful woman, but then morphs into its true form: a deadly hypnotica!) Crankshaw: "Dr. Mindstrong, Captain Ryan has fallen under control of a deadly hypnoticon!" Captain Ryan: "How about some sugar, baby?" (the hypnotica licks him) Donatello: "Oh, you're missing a great one, Leo!" (nothing else happens)"
"Raphael: (discovering a bite mark on his right arm) "Did you bite me?!" (Leo smiles sinisterly) "YOU BIT ME!!""
"Donatello: "Here it is. The parasitic wasp infects animals with a virus which brainwashes them into protecting its eggs." Michelangelo: "You think that's the kind of wasp that stung Leo?" (hears Leo and Raph trying to open the door and panics) Donatello: "The mutant version...then Leo bit Raph, and passed the virus to him." Michelangelo: "So, once the egg hatches, will the guys go back to normal?" Donatello: "Not quite. (Shows a picture of a caterpillar guarding the wasp egg) Look what happens to the caterpillar guarding the egg." (The wasp hatches in the picture, comes closer to the caterpillar and starts eating it) Michelangelo: "It's eating him! IT'S EATING HIM!" (screams) "What are we gonna do?" Donatello: "Well, I might be able to create some kind of antibody. But first, I need a sample of the virus from the egg.""
"Leonardo:(in calm and slow but yet suspicious voice) "Donatello...Michelangelo? What happened?" Michelangelo:(in a reassured voice) "Leo! You went crazy, dude. So did Raph. He ran off with the egg." Leonardo: "Don't worry, I'm better now. You can untie me, Mikey. Untie me, so we can go find Raph together." (Mikey is just about to untie him, but Donnie stops him) Donatello: "No! Don't do it Mikey! Look at his eyes." (Leo's eyes got back to black and he tries to bite Mikey and break free) Leonardo:(in demonic metallic echoing voice) "IT IS USELESS TO RESIST! IT IS ONLY A MATTER OF TIME BEFORE THE EGG BURSTS AND THE HATCHLINGS WILL FEED ON US ALL!!!"(Donnie slaps him.) Donatello: "Sorry to burst your possessed bubble Leo, we may not have the egg but a sample of your blood should help me create a cure." Michelangelo:(gasp) "Bite! You've been bitten! You've been bitten!" Donatello:(notices the bite mark on his neck) "I must have gotten during the fight and now.... I'm infected too." (Mikey whimpers)"
"Donatello: "You finished the antibody yourself?" Leonardo: "And you were just pretending to be one of us?" Michelangelo: "YEP!" Raphael: "But, that's smart." Michelangelo: "Yeah it is! Just call me Dr. Einstein...enstein!" (the others groan) "Oh, I forget to mention. It may cause drowsiness." (the others faint from sleepiness)"
"Leonardo: "You did save are lives, but, you also used my favorite comic book as toilet paper!" Michelangelo: "Well, I only did that so you'd chase me." Leonardo: "Well, it worked!" Michelangelo: "Wait, stop!" Leonardo: "Mikey!" (Leo pins Mikey to the ground, then prepares to "finish him off" with a mop, while his brothers watch, clearly amused.) Michelangelo:(Panicky) "I'M A HERO!!!!!""