The story is about a boy named Greg Heffley. Greg is having an ultimate summer fantasy of his life, but Greg is only spending his whole summer just playing video games inside his house with lights turned off. Soon he recognizes that summer would be fun. The main character for this story is Greg Heffley. Greg, a self-confessed “indoor person”, is living out his ultimate summer fantasy: no responsibilities and no rules. Frank Heffley is Greg’s father. He has a strong interest in U. S. history, especially the American Civil War, and even made a replica of an American Civil War battle field. Susan Heffley is Greg’s mother.
She tries hard to be a good, loving, and dedicated mother and wife, but she constantly does something wrong in her efforts. Rodrick Heffley is Greg’s older brother and is a major antagonist of the series, since he often blackmails Greg. Manny Heffley is Greg’s younger brother who is “spoiled” by his parents. Rowley Jefferson is Greg’s best friend, although Greg views Rowley as dumb, childish, and ignorant. Fregley is a repulsive, disgusting, dorky, and weird kid, is a repulsive, disgusting, dorky, and weird kid. Heather Hills is Holly Hills’ older sister who’s in Rodrick’s grade, and Greg has a tiny crush on her.
She is also alphabetically put after Rodrick. The book opens describing Greg’s worst summer ever beginning with Greg Heffley and Rowley Jefferson going to Rowley’s country club after school closes for the summer, but Greg is kicked out due to his complaining of the smallest of predicaments. The beach trip that he was looking forward to is canceled because the money went tight, so the Heffley’s resort to going to the town pool, which Greg hates because of its hairy and rotund visitors. Later, Greg and Rowley have a sleepover together, and watch a horror movie taken from Rodrick’s room.
After the movie, Greg and Rowley soon become paranoid on account of a muddy hand that might strangle them, which was in the movie. Unfortunately for Greg, his mother, Susan finds out about the movie after Greg’s father told her when he found them sleeping in the bathroom, and then she starts a reading club in which he is the only participant after two days. The reading program, however, is put to a stop when Mr. Jefferson arrives with a huge bill that Greg and Rowley spent on fruit smoothies at the country club, and he forces Greg and Rowley to pay it off. Greg and Rowley decide to do a lawn care service to pay the debt, but Mr.
Jefferson only makes them one flyer for their business, after he tells them they can’t use his computer. Their first customer is Mrs. Canfield, who lives on Greg’s grandmother’s street. Unfortunately, the job does not go well, as the boys never used a lawn mower before, all the gas leaks out of the mower, and the instructions are in Spanish. When Greg tells Rowley he needs to do most of the work while Greg counts the money, that made Rowley angry and he quits. Greg mows Mrs. Canfield’s lawn by himself, but she refuses to pay him because he didn’t mow all of her lawn because of the dog poop on there.
Greg’s birthday soon arrives, but the gifts he receives are all gifts he hates, including a useless cellphone that only calls home and 911. This is because Greg’s parents believe that he, like his older brother Rodrick, will just rise the bill up if he gets a regular cellphone. Greg gets money in every card he receives, but Susan, his mother, confiscates it to pay off Mr. Jefferson. Uncle Joe’s dog, Killer, eats much of Greg’s cake, thus “ruining” his birthday. The following day, he and Rodrick both get fish as a makeup gift, even though it wasn’t Rodrick’s birthday, which Greg dubbed as “unfair”.
However, when the family takes a trip to a water park, Rodrick’s fish eats Greg’s fish after Susan puts Rodrick’s fish in the same bowl because Rodrick didn’t feed the fish or clean the bowl once and was starting to feed off the algae growing on it. The next day is Father’s Day, so the Heffley’s visit Leisure Towers to spend the day with Greg’s grandfather. There, Frank tells of how his dog, Nutty, ran away to a butterfly farm. Greg’s grandfather reveals that he had actually run the dog over and Greg’s father takes off in disgust.
He then buys a dog which Susan names “Sweetheart” and shortens to “Sweetie”, even though the dog is actually male. Even though Greg has wanted a dog for a long time, he quickly becomes annoyed at Sweetie, who naps on his pillow, sleeps on his bed, and “won’t stop barking” at the TV, and the only way that gets him to stop barking is when a commercial with gophers popping out of their holes comes up. Greg’s mother keeps making Greg go to the town pool with her and Manny, which Greg agrees to only to hang out with Heather Hills, who is a lifeguard there.
Greg tries to make a good impression to her, even though she barely pays any attention to him. One day, Greg decides to end the so-called “relationship” when he makes her clean a kid’s vomit and was too sick to clean it himself after he had to save Manny from the naked shower people. The Jefferson’s later invite Greg to go to the beach with them, which is where Greg had wanted to go, but he realizes it was far from what he expected, where he begins to have a breakdown from no electronics, almost got jumped by teenagers he pulled a prank on, and especially the Cranium Shaker, which almost makes Greg vomit.
He tries to entertain himself, but he is sent home after he snaps a rubber band at Rowley. Susan later tries to get Frank and Greg together, but both of them realize that they should keep their distance. She even got them tickets for a baseball game, but Greg thought Frank was trying to get rid of him for the incident that happened earlier, and calls the police on him, only embarrassed to discover the truth. To get out of it, they had to give the two cops their tickets.
However, they both hate much of the same things, such as a comic named Li’l Cutie, where the writer has retired and passed it on to his son (who was possibly the basis of the character when he was little) and has made the comic even worse. Later, Sweetie is given to Greg’s grandmother for company after her old dog Henry died. The book ends with Greg realizing that summer is over when he sees a photo album titled “Best Summer Ever! ” It is a “horrible record” of that summer to Greg, but Greg writes that the person who had taken the pictures had told the story.
