In an attempt to get out of his monthly bath, Timmy has Cosmo and Wanda poof him to his favorite comic book store. Unfortunately for Timmy, he forgot to say "And keep my clothes on!" At the same time, in his magic comic book, the Crimson Chin battles his water based enemy - H2Olga! And since the comic book is slowly sinking into Timmy's tub, Olga is getting more and more powerful! Will Timmy be able to complete his naked dash across town in time to save the Crimson Chin?
Timmy's parents are trying to convince him to take a bath, but he does not see why... because the dirt is blocking his eyes. Mr. and Mrs. Turner, dressed in biohazard suits, snatch Timmy with a mechanical grabber and drop him into the bath. Timmy's parents say that now he is ten, they can trust him to take a bath alone, so they leave Timmy but not before shutting the door, locking it, welding it shut and stacking furniture in front of the door so Timmy cannot get out. Timmy relaxes in the bathtub and decides to pass the time reading a Crimson Chin comic book. Cosmo and Wanda are in the bathtub disguised as goldfish, wondering to themselves why they are swimming in Timmy's filth. When Timmy opens the comic book, he realizes its the last month issue featuring the villain H20lga, who "retains water AND evil". Timmy wants a new comic for his reading, so he wishes himself to the comic book store.... unfortunately, he forgot his clothes.
At the comic book store, Timmy stands naked while the tail of a cat-woman like superhero's cardboard cut out blocks his private parts. He screams when he realizes that Cosmo and Wanda forgot to put him back in clothes. Two nerdy kids nearby hear "the scream of Naked Lad" and corner Timmy, asking for his naked autograph and to see his super naked speed. Back in Timmy's bathroom, Cosmo and Wanda decide to have a contest to see who can hold their breath underwater the longest, even though they are fish. Meanwhile, this entire time the Crimson Chin's comic book has been sparkling with magic energy. The panels inside the comic begin to move, and they show another story.
Beverly Boulevard, a "non-super powered reporter" for the Daily Blabbity, asks Charles Hampton Indigo (the poorly disguised journalist identity of the Crimson Chin) to babysit her baby niece. Chin agrees, only because of hopes that by doing something nice for Beverly, he can win her over. After she leaves, Chin quickly runs into problems when he asks how much trouble one baby could be. Soon after asking himself this question, the baby poops her diaper, causing it to sag with the weight of her poop. To make matters worse, the baby vomits all over him. The mess in her diaper causes her to cry. Crimson Chin attempts to change the loaded diaper but ends up putting the new diaper on his giant chin instead. He finally gets it right and sighs in relief, when suddenly they hear the cries of help of "a hefty man". Chin grabs the baby and flies off.
Back in the real world, Timmy is trying to sneak through Dimmsdale, running and hiding behind benches, mailboxes, and other street objects every time traffic passes by and blocks the view of him. He realizes he needs to get back home in ten minutes, or his parents would find out that he didn't take a bath and kill him, or worse, make him take another bath. When Timmy passes by a TV store and watches one of the screens in the window, the Mayor of Dimmsdale and Chompy the Goat appear on the screen at a televised press conference, announcing that Dimmsdale had installed cameras on every street corner and traffic light. The Mayor allows Chompy to press the ceremonial button, which activates the cameras across the city. The cameras catch Timmy naked, the mayor yells for Chompy to shield his eyes. Timmy realizes the cameras can see him and screams, running down the street and using his pink hat to cover himself. He realizes he will be alright as long as his parents don't need to use the bathroom. Back home, Mr. Turner challenges his wife to a water drinking contest.
Meanwhile in Chincinnati, in the comic book (which is starting to slide closer and closer toward the water in Timmy's bathtub), the Crimson Chin flies into the city park carrying the baby with him, searching for the source of the hefty man's screaming. But it turns out that the hefty man was actually H20lga, a rotund woman with a Russian accent who was made entirely of water. She had led the Crimson Chin to a trap. Luckily for the Chin, all her powers could do was cause a nearby water fountain to squirt water into his eyes. Crimson Chin proclaims that "THIS IS A CITY!" and that there is no body of water large enough there for H20lga to smite him. But then, the comic book falls into the water, and H20lga uses the body of water from the real world to become stronger and defeat the Crimson Chin in the comic book. She steals the baby, intending to raise her to be evil.
Timmy is making his way through Dimmsdale using a newspaper to cover himself, the newspaper reads that a "Naked Terror Stuns City!" and that Chompy has been scarred for life. Timmy decides to take a shortcut through the Dimmsdale Museum of Natural History. Chester, A.J., Sanjay, and Elmer happen to be taking a tour there at the moment. Apparently, A.J. had dragged them all there because they had a cool new exhibit on the solar system, but Chester really doesn't care. The tour guide brings them to the exhibit, exclaiming "Behold the glory of our universe!" before unveiling the curtain. Timmy was hiding behind there, the four boys stand in shock and horror as Timmy shows his butt in front of the moon. Chester jokes "Nice moon, glad we came". Back in the comic book, Crimson Chin takes a pounding from H20lga. Worse, the comic book is sinking further into the tub, which Crimson Chin sees a tidal waving heading to engulf Chincinatti. He rescues the townspeople by ripping up the asphalt and using it to create his wave that launches everyone on top of a skyscraper. They are saved temporarily, but now H20lga has grown into a giantess and captures the Crimson Chin. She threatens to soggy up page 8, Chin says that is where the staples where and that the comic book would fall apart if he does not stop her.
The Crimson Chin spots the baby girl hanging from a flagpole by her diaper and notices that the diaper is extra absorbent. He distracts H2Olga so he can vaporize her arm to get himself free. After vaporizing part of H20lga's arm to get himself free, Chin flies over and scoops the baby up and uses her diaper to absorb all the water and H20lga. Chincinnati is saved. H20loga swears to the Chin that she will get him, but is interrupted by the baby who makes a grunting face before farting and pooping her diaper yet again, which H20lga is trapped in. H20lga screams as the baby poops on her, to which the Crimson Chin says "If you live a life of crime, you'll always be... number two!". The camera pans to the comic book, which is promptly knocked over out of the tub and out of danger when Cosmo and Wanda emerge from the tub wearing snorkeling gear. Timmy appears outside the window, meanwhile causing three skateboarders to crash when they mistake him for Naked Lad. Timmy's parents are right outside the bathroom door and really need to poop because of the prune juice and laxatives. They rip down the door just as Cosmo and Wanda poof Timmy back into the bathtub. His father grabs him and throws him out of the bathroom saying that he is "clean enough". Timmy is still naked but relieved that he is at least naked in his own house. Cosmo, however, appears naked much to the chagrin of Wanda.