It’s the second instalment in the Dog Man story, and evil Petey the cat has unsuccessfully cloned himself, producing a cute kitten, adopted by Dog Man (half dog, half cop). Aided by the amazing robot 80-HD (say it out loud to get the joke), the three Supa Buddies might just be the superheroes everyone’s been waiting for. Only, before they can get going, Petey steals the little kitty away. After a strangely familiar origin story of children transported to a distant island, surviving without the civilising influence of society or parents, Petey reveals that his enemies are after him – and he must protect his kitty clone. Dog Man is still unhappy about what happened from Chapter 3. When he came to his doghouse, he notices Chief, Milly, Sarah, and Zuzu on the TV news. Dog Man and 80-HD go into their superhero alter-egos and run off to save them.

Mega Robot Petey sneaks up behind the Fleas, as Petey tells LP the plan: LP should stay there while Petey sneaks out here so he can shrink the Fleas, without hitting LP's friends. Petey carefully aims the shrink ray at the Fleas, but then LP sneaks up behind him and shouts "Hey, Petey!", causing him to accidentally drop the ray on the ground. The Fleas suddenly notice the two cats. They are about to zap them with their killer death ray, but it instead destroys Mega Robot Petey's exoskeleton. George and Harold are in fifth grade, and their teacher is making them read classic literature. When they read Lord of the Fliesit inspired them to write a novel.

At the police station, Chief gets a phone call from the Cat Jail saying there's been a jail escape, as Chief asks where, then the phone says it's at the jail, (cause Chief has a problem with forgetting stuff), Chief then says oh as he says he'll put his best man on it as he hangs up and calls Dog Man. Then Milly tells him that Dog Man is late for work again. An angry Chief calls Dog Man and tells him to meet up at cat jail in ten minutes and not to get distracted while he's at it. Dog Man then runs to the jail, when a squirrel runs next to him and, as usual, Dog Man gets distracted and runs after the squirrel, as the squirrel runs up the tree, Dog Man runs to it and starts barking at it. Petey and Li'l Petey are still on their escape from town, but LP wants to save Chief, Milly, Sarah, and Zuzu, but Petey says that the only thing they have is an old shrink ray, which only has two shots left, and besides, he can't go out looking like a hero. LP tells Petey that he should switch expectations, causing Petey to decide to save his friends, but only if LP should stop calling him "papa". Meanwhile, Petey and Lil Petey are still on their escape from town, but LP wants to save Chief, Milly, Sarah, and Zuzu, but Petey says that the only thing they have is an old shrink ray, which only has two shots left, and besides, he can't go out looking like a hero. LP tells Petey that he should switch expectations, causing Petey to decide to save his friends, but only if LP should stop calling him "papa".

Piggy then decides to tell them a "funny" story: "Once there were three evil villains who build a Giant Robo Brontosaurus that had a killer death ray." The Robo Brontosaurus zaps its death ray at a building, which crashes onto them. "You were right," laughs Cat Kid. "That WAS a funny story!" Now comes the chance to save Chief, Milly, Sarah, and Zuzu. Cat Kid flies up to them and cuts their shirts and the Bark Knight catches them with the Dogmobile's giant baseball glove. Unfortunately, the Dogmobile is about to crash into a factory, so when Dog Man steps on the brake too hard, it sends Chief, Milly, Sarah, and Zuzu flying off the glove, about to smash into the factory. Piggy is based on another Piggy in Lord of the Flies. The Piggy in Lord of the Fleas is a Megalomaniac (possibly an Undertale reference), though. One of the Dogmobile's buttons say, "Weird Al Music", a nod to the Weird Al Yankovic, since he created the theme song for the Captain Underpants movie. Petey's story began when he was in jail and he was working on something (a giant robot of himself). A guard came in to tell him he has to see a psychiatrist, and that's when he met up with Dr. Katz. The cat psychiatrist demanded him he needs to get to the root of his problems. Petey explained to him that when he was a kitten (looks like Li'l Petey), he used to be in the Critter Scouts. One day, when they came to a mini golf game, the scout leader left to get some coffee. Everything started out great, but then a great storm arose. The place began to flood and the scouts hopped on a boat-like structure in Hole 4. The storm raged for what felt like weeks and finally they landed on a deserted island. Bub asked what they'll do now. Petey explains that they'll use their scout skills to survive. They could hunt for food, and use Piggy's specs, which are his glasses, to light fires, and together they could build a utopia.Piggy then decides to tell them a "funny" story: "Once there were three evil villains who build a Giant Robo Brontosaurus that had a killer death ray." The Robo Brontosaurus zaps its death ray at a building, which crashes onto them. "You were right," laughs Cat Kid. "That WAS a funny story!" Now comes the chance to save Chief, Milly, Sarah, and Zuzu. Cat Kid flies up to them and cuts their shirts and the Bark Knight catches them with the Dogmobile's giant baseball glove. Unfortunately, the Dogmobile is about to crash into a factory, so Dog Man steps on the brake too hard, it sends Chief, Milly, Sarah, and Zuzu flying off the glove, about to smash into the factory. Genuinely laugh out loud, it’s exactly the kind of silly humour kids love and are familiar with, while being clever (in this case, a re-versioning of Lord of the Flies), succinct and highly original. When the cops reach the Cat Jail, they see that there is a Giant Robo-Brontosaurus is at the parking lot, and Dog Man is still distracted by squirrels, so they decide to go in without him.

Once he gets there, he excitedly jumps on Chief, who is fed up with this antic, while Milly points out that the animals are running away in their Robo-Brontosaurus. Angered, Chief scolds to Dog Man that he made the bad guys get away and forces him to go home. Dog Man, depressed, leaves to his doghouse, while Chief, Milly, and Sarah follow the animals.However, nobody really knows where the F.L.E.A.S have gone, and Dog Man starts itching his fur which, coincidentally, is where the F.L.E.A.S. are. this is the third book to have a bonus mini-comic. the first is Dog Man: Unleashed, and the second is Dog Man: A Tale of Two Kitties. Despite his doggy ways, Dog Man is actually terrific at catching the terrible criminals that plague his town, so when Petey tries to engineer a coup to replace the Chief of Police, Dog Man saves the day.