The day starts off with a villain and his powerful metal dog, with a few hundred times the size, speed and viciousness of a normal one. Johnny Rancid, his creator, is urging him to destroy the city and is succeeding when the Teen Titans show up. They unite, demolishing the dog and capturing his maker after a brief battle. Robin: We're shutting you down, Johnny.
Raven: And your little dog, too.
After their victory, they head back to the Tower and to their horror; find that their place has been trashed. The control room is in total disarray with a humongous mess to clean up and personal items are strewn everywhere. Food is scattered on the floor and the sofa, including anything remotely edible. Their jaws drop, and while they are cleaning up the room, some start complaining about the intruder/intruders having destroyed or messed up their things.
Starfire: (Staring at the mess) There was a party and we were not invited?
Robin sends the other four to investigate while he searches another part of the Tower. As they start, Raven questions Beast Boy if he knows anything about the intruder as he is known to have secretly kept rather destructive animals before. Beast Boy becomes edgy with Cyborg pressurizing him as well and avoids answering them. Suddenly, he shouts out "There! I saw something move!" pointing to the far end of the corridor. Raven and Cyborg take off, racing in the direction which Beast Boy was indicating to find the 'something'. Starfire is about to follow when Beast Boy grabs her, opens a door next to him and pulls her into his room, bolting it securely. Starfire is puzzled with his actions and makes an attempt to join the others. He tells her that he has a pretty good idea who the intruder is. Starfire, puzzled, asks "Then why do you not tell the others?" Beast Boy brings her through a short cinematic with picture film, connecting this episode with the one where Killer Moth wants to destroy the city with his metal-eating Mutant Moths, and will only stop if an unwilling Robin agrees to take his delighted daughter, Kitten, to the prom. Beast Boy: (To Starfire) Remember when Killer Moth made an army of mutant moths and forced Robin to take his daughter to prom, and he was like "Erg..." and you were like "GRRR!!" And Robin was like "Argh...!" But then we found Killer Moth, and I was like "Dude!" And Raven was like "Bzz!" And Cyborg was like "Boo-yah!" And we kicked his butt, and the mutant moths turned back into these cute little wormy things?
Starfire's eyes start spinning and when the pictures are finished, Beast Boy holds up a white, gurgling baby Mutant Moth in worm state. She is shocked. Beast Boy pleads her to take in Silkie, as he named the grub, and desperately wants to give him to her, but Starfire refuses. She wants Beast Boy to hide Silkie in his own room, but he points out that Raven and Cyborg are certain to check it when they return from their wild-goose chase, and that she is his only hope. Sighing, Starfire reluctantly holds out her arms to take Silkie and turns her face away after much persuasion from Beast Boy.
However, when Starfire looks into Silkie's eyes, she starts to love Silkie as she thinks he is adorable and starts imagining taking Silkie out to the park, Silkie graduating from school and many more happy pictures. She tells Beast Boy she would be delighted to take Silkie when there is a knock on the door. At lightning speed, Beast Boy flings open his window and shoves her out; urging her to fly to her room as he's sure Raven and Cyborg are at the door. He fastens the window, then coolly walks to the door and unbolts it. Like he expected, a glaring duo are waiting outside. "Mind if we have a look around?" blandly questions Cyborg as they step in. Both don't look very pleased but have VERY suspicious looks on their faces, considering that it seems Beast Boy gave them a wrong trail and is now in his room instead of going to search with them. "Come on in, I've got nothing to hide. Nothing to hide", says Beast Boy with a grin on his face, and cheerfully waves them in.
Meanwhile, Starfire has brought Silkie to her room and he has started to cry. She does not know what Silkie wants until she hits a realization---food! She puts him in a baby feeder and offers Silkie every food she can think of, but Silkie refuses it all and continues to keep up his racket. Starfire: What do Silkies eat? Fruit? Cereal? Toast? Candy? Celery? Steak? Nachos? Mustard? Rutabega? Tofu?
(Silkie turns his head away and refuses each offering and continues to wail) Starfire is desperate and decides to offer Silkie Zorka berries from her homeland, Tamara. To her delight, Silkie loves the berries and dives into them---literally. Starfire turns her back on him for a few seconds, and doesn't notice Silkie crawling inside the jar the Zorka berries are kept in and start to gobble them all up. When she finally faces Silkie, he has eaten so many radioactive berries; he's mutated into a huge, giant Silkie worm, about half the size of Starfire's room. She is stunned and exclaims how much Silkie has grown while he sniffs around for more food. He finally decides to try a delicacy of Starfire's curtains. She tries to restrain him, but since he is quite a few times larger than her, the outcome is easy to predict. Disaster strikes when there's a knock on her door. Starfire panics when she discovers its Raven and Cyborg, with a gigantic Silkie to hide. Unfortunately, she can't find a good hiding place, while Raven and Cyborg are getting impatient. She finally slides out of her room and speedily closes the door before they can have a look in. She innocently asks them what the matter is, and they explain that they have searched the Titan Tower and found no sign of the intruder; only, they haven't searched in Starfire's room. Starfire tries to laugh it off and pleads with them not to go in. Raven and Cyborg are determined; however, so Starfire ends up by saying her room is messy as they drag her in, which is a bit odd since Starfire's room is as tidy as can be. Everything is neatly in place and in the right order, except the curtains.
Cyborg: We've searched all over the Tower and there hasn't been any sign of the intruder. The only place we haven't searched in is…
Starfire: My room!
Starfire: (About her room) Please, do not go in, it is very…
(They go in anyway; Cyborg by the door and Raven through the walls.)
Starfire: (Ends off as they drag her into the room and Silkie is nowhere to be seen)… messy. (Smiles and hovers in front of Cyborg and Raven, partially blocking their view)
Cyborg: This is messy? Girl, have you seen Beast Boy's room?
Luckily, Silkie is nowhere to be seen while the room is being searched, but Raven notices the half-eaten curtains.
Raven: So, you and the curtains got in some sort of argument?
Starfire: (Quickly) Yes, today is Glorb Glorb, the Tamaranian festival of berating drapery. STUPID CURTAINS!!! (Blasts curtains with eye lasers, leaving a gaping hole in the wall)
To Starfire's relief, Raven and Cyborg finally leave, deciding they should start searching more thoroughly, but Silkie's whereabouts are a mystery ---until she finds a Silkie-sized hole under her bed. She tries to find Silkie at night, hoping no one will notice her, but Robin interrupts.
Starfire: (Floating around the control room at night and saying very softly) Here Silkie... here, Silkie, Silkie. Your k'norfka wishes to locate you…
(She yelps, so badly surprised that she tumbles to the floor; now both can be seen in the moonlight shining in from the window. Robin has a piece of a couch cushion) Robin: Um... where's the sofa?
(She looks in the direction he is indicating, except for the cushion he holds and a few others scattered about the floor, the sofa is now gone; time for a little quick thinking from Silkie's would-be mommy)
Starfire: Uh... your Earthly ways are strange. (Edging away) Please, what is this "so-fa" of which you speak?
(Before Robin can react, she has made it to the side door and given him a little giggle)
Robin looks unconvinced, and Starfire speeds off to find her pet before he can cause more destruction. She finally finds him in the basement --- attacking Cyborg. Or to be precise, slurping off and eating an angry Cyborg's leg. As the Titans prepare to attack (and Cyborg gets really mad about his best leg), she quickly prevents them from hurting Silkie and confesses.
Raven (in a dry voice): He attacked Cyborg.
Cyborg (indignantly): He ate my best leg!
Starfire: No! Don't harm Silkie! He is my Bumgorf!
Raven: What's a "bumgorf"?
Beast Boy: That's Silkie? Dude! What have you been feeding him?
Even Beast Boy is shocked at Silkie's sheer size. Starfire tries to convince Robin to keep him by saying he is not very destructive. Sadly, she is proven wrong when Silkie drags her off holding onto his lead as he spies yet another food to try. When Silkie chomps through layers of the Titan Tower and is within seconds of destroying it, it's the last straw, and Robin decides that they can't have him. Starfire has to abandon her beloved pet on a deserted island in space. She gives a happy, gurgling Silkie a bath on the island pool with a sponge and uses her laser-powers to carve a message on a rock, telling people to be good to Silkie. When Starfire has done all this, she sadly bids farewell to her pet and slowly starts to leave. Silkie realizes that his protector is leaving him, and instantly uses one of his legs to grab hold and bind her in mid-air, stubbornly refusing to let go. Starfire vainly struggles to free herself from her pet, but to no avail. In the end, Starfire has to blast Silkie with her powers to make him let go of her. She flies away with tears in her eyes as a wounded Silkie is shown as confused and upset. Suddenly, a dark silhouette, Killer Moth, appears on the island, laughing while gleefully eying Silkie.
The next scene shows Johnny Rancid back again with a new monster dog, bigger and stronger. However, even as the Titans prepare to fight, both he and his dog are swallowed by an enormous Mutant Moth, ridden by Killer Moth himself. With a jolt, Starfire realizes it is---Silkie? Starfire is shocked and staunchly refuses to fight her former pet. The Titans try their best, but it's hopeless, they need Starfire. One by one, they are driven back. Robin manages to land on Silkie's back and challenges Killer Moth to a fight, but loses. Seeing her friends being hurt decide Starfire, she has to and WILL fight Silky.
Starfire: I must help my friends, even if it means harming my Silkie.
She urges Silkie to stop fighting them and turn against Killer Moth. Finally, Silkie has to make a hard choice. Who will he listen and go to, his creator, Killer Moth, or the person who cared for him, Starfire? He cannot decide and is so stressed that he eventually explodes into purplish goop, completely covering the Titans. Raven is not very happy and wants to get clean as soon as possible. Cyborg, on the other hand, is delighted, because he has found his best leg again. Cyborg (happily): My leg!
Beast Boy: He wasn't mutating! He was molting.
Raven: Fascinating... Can we go home now? I need a shower in the worst way.
Starfire is heart-broken at Silkie's explosion and starts searching frantically for him. Just when she has lost all hope, a small sound amidst the goop calls her attention. Starfire dives to the source and discovers Silkie! The two are finally reunited. Seeing Starfire so delighted and a smaller, probably less destructive version of Silkie melts his heart, Robin decides baby Silkie can stay in the tower. Starfire is on cloud nine and when she sees Silkie eating up the goop, her adventurous spirit leads her to scoop up a little and cautiously taste a bit. The other Teen Titans are SERIOUSLY freaked out (no wonder), in fact, they all go like "EEWWWWW!!!", but Starfire loves it.
Robin: All right, I guess he can stay. (Smiles)
Starfire: Oh, it tastes just like Zorka Berries!
(She and baby Silkie happily eat the goop on the street where Mutant Moth Silkie exploded.)
(All the Titans except Starfire freak out)
Robin: (Grossed out) Err... Should we try to stop her?
Raven: (Equally grossed out) That stuff's gotta get cleaned up somehow.
The show ends with the Teen Titans starting to walk back to their tower, with the exception of Starfire, who is happily finishing up the goop with her beloved Silkie, creating a heart-shaped figure while eating it.