Monday. It’s the first day of October, and Greg is already looking forward to Halloween. He loves trick-or-treating, although his mom says he’s too old for it. Greg’s dad likes Halloween too, since he hides in the bushes and sprays passing teenagers with water. Greg’s mom takes Greg and Rowley to the Crossland High School haunted house. When Rowley shows up, Greg is embarrassed to see that he’s wearing his Halloween costume from last year. At the haunted house, Greg and Rowley are frightened by a teenager with a chainsaw. Greg’s mom confronts him and gets him to show that the chainsaw is fake. Greg is grateful, although he also feels humiliated.
Greg likes to think of himself as very mature, but in reality he still displays childish behaviors and interests. For example, he still enjoys trick-or-treating for the free candy, although his mom thinks he’s too old for it. Similarly, although he thinks he can handle the frightening content of a haunted house, he is terrified by the chainsaw-wielding teenager and is grateful for his mother’s intervention, even though his humiliation suggests that he wishes he didn’t need it.
Saturday. Greg decides to make a haunted house of his own in Rowley’s basement (without parental permission). His ideas include a maze of 1,000 skulls, an acid lake, and a “Hall of Screams.” He makes posters advertising the haunted house that claim there will be live sharks. That afternoon, there is a line of kids waiting to visit the haunted house. Greg charges them two dollars instead of fifty cents, sensing a business opportunity. Greg and Rowley admit a kid named Shane Snella into the “Hall of Screams,” which is a bed with him and Rowley on either side of it. Shane is terrified and hides underneath the bed. Rowley’s dad comes downstairs and shuts down the haunted house, but Greg is pleased that at least they made two dollars.
From the beginning, Greg and Rowley’s haunted house is clearly a bit of a scam, charging local kids two dollars for their hastily thrown together displays. In this way, they are more concerned about their own self-interest than the value they are bringing to others. When Shane enters the haunted house, they are insensitive to his age and fears and they end up terrifying him—prompting Rowley’s dad to shut down the haunted house, thinking they are bullying Shane. Greg’s focus on their two dollar profit suggests that he hasn’t quite learned his lesson.
Sunday and Tuesday. Rowley is grounded as a punishment for the haunted house, and Greg is annoyed that he can’t play video games at Rowley’s house anymore. To make it up to Rowley, he gives him a play-by-play of one of his favorite television shows over the phone. Greg admires Rowley’s new knight costume, which comes with a sword and shield. Greg admits that his own costumes are usually more haphazard and last-minute, like a toilet paper mummy or a cowboy with two baseball caps. However, he says that he has to spend most of his time planning the best trick-or-treating route designed to gather the most candy.
Greg is not always the best or most loyal friend to Rowley. For instance, although it was Greg’s behavior that got Rowley in trouble in the first place (he suggested that they open the haunted house), he doesn’t do much for Rowley when he’s grounded except telling him about television shows that Rowley is no longer allowed to watch. This is hardly going to make Rowley feel better, although Greg seems to think it will—suggesting his lack of sensitivity to his friend’s needs.
Halloween. Greg is still stumped about his costume, but his mom brings him a pirate costume at the last minute. Rowley’s mom, meanwhile, has made so many “safety improvements” to the knight costume that it doesn’t look much like a knight anymore. Greg’s mom tells him to take Manny with him on the trick-or-treating trip, which leads to Greg’s dad coming as well, along with a neighbor friend. Greg is frustrated by their slow progress as a result of having the adults and the “little kids” along.” After the rest of the group goes home, he and Rowley make up for lost time by trick-or-treating until 10:30 P.M. that night.
Greg is frustrated that the group of younger kids is slowing down his trick-or-treating progress, since he and Rowley are supposedly old enough to go out on their own. Ironically, however, they aren’t exactly entirely independent: Rowley is wearing a Halloween costume sewn by his mom, with “safety improvements.” Furthermore, they are going in search of free candy, an activity usually associated with children.
On their way home, Greg and Rowley have a run-in with a few teenagers who spray them with a fire extinguisher from a pick-up truck. After Greg shouts that he’s going to call the cops, Greg and Rowley flee to Greg’s grandmother’s house, pursued by the teenagers. Greg’s mom calls to say they have to be home, so they run home, this time narrowly escaping the pick-up truck. After this ordeal, Greg’s dad drenches them with water, ruining all their Halloween candy.
Greg and Rowley are gratuitously bullied by local older teenagers, presumably just because the teenagers are bored and spend their time spraying younger kids with a fire extinguisher. In this sense, the community of Greg’s middle and high school clearly perpetuates a cycle of bullying in which older kids pick on their younger peers.