Diary of a Wimpy Kid: The Last Straw

The book begins on January 1, with Greg talking about his family's New Year's resolutions, and about how he struggles to think of one for himself. Life becomes more difficult for Greg and his best friend Rowley when their school bus route is "rezoned" to the Whirley Street neighborhood, so they have to walk to and from school.

Greg also deals with being compared to the sons of his dad's boss, who all play sports and always seem to be outside exercising. Frank is jealous of this and wants his sons to be like his boss's sons. After conflicts over Greg wanting to stay inside and watch TV on Saturdays and Frank stealing his school snacks, Frank makes him sign up for intramural soccer. The last straw is an incident at church on Easter, where Greg accidentally gets chocolate on the back of his pants. He refuses to enter the church with the stained pants on for fear of his crush, Holly Hills, mistaking it for poop, so his mother allows him to use her sweater like a kilt. Greg gets bored during the lengthy service and teases his little brother Manny, causing Manny to throw a tantrum. The Heffley family is forced to leave, and Frank's boss saw everything, resulting in Frank becoming even more embarrassed than Greg, who had to walk past Holly.

Greg does not like his coach, Mr Litch, who yells like a drill sergeant and runs intense drills during practice. In order to get out of this, he volunteers to be the backup goalie, but becomes the starter when the main goalie is injured. He takes a break to pick dandelions on the field, which ultimately costs his team the game. Frank is beyond embarrassed when his boss shows it to him in the paper, and does not speak to Greg at all that evening.

Later on, Frank runs into a neighborhood troublemaker named Lenwood Heath, who has apparently reformed after going to military school. Impressed with his former enemy's turnaround, he decides to sign Greg up for a summer program at Spag Union Military School, hoping Greg will change for the better but mostly hoping to end the embarrassment.

To impress his dad and thereby avoid military school, Greg decides to join the troop 133 Boy Scouts. Another reason is to allow him to quit soccer, as Boy Scout meetings are on Sundays. However, he gets sick and misses their camping trip, which Frank, as a chaperone, has to go to anyway. Frank ends up in the emergency room after two of the kids he was in charge of get into a fight and one gets seriously injured. Later, when Greg, Frank, and Rodrick have a camping "do-over", they end up at a hotel after heavy rain, where Rodrick tricks Greg into thinking Holly and her family are staying in the room across from theirs, and locks Greg out of their room in his underwear.

After this, Greg becomes more resigned to his military school fate, especially after multiple unsuccessful attempts to make a good impression on Holly. He gives up for good when he attempts to ask her to join him for a round at the roller skating rink, only for Holly to mistake him for Fregley, a weird kid whom Greg does not even wish to be associated with. Even worse, on the last day of school, Greg gets jealous upon finding a very sweet note from Holly in Rowley's yearbook.

On what is supposed to be his only day of summer vacation being sent to Spag Union, Greg is forced to spend it with his family at a birthday party hosted by their neighbors, the Snella family. The party features a contest where all the adults have to perform silly acts to make the baby laugh, while the Snellas record the acts to submit to America's Funniest Home Videos in an attempt to win a prize. Greg notices that Manny has found their mother's gift for the baby, a blanket just like the one Manny got for his first birthday. He tries to stop Manny from taking the blanket for himself, but Manny throws it onto a tree. Greg attempts to climb the tree to retrieve the blanket, but he gets stuck and calls for help, only for his pants to fall down and reveal his Wonder Woman underwear (which he only wore because he had fallen behind on his laundry). The Snella family managed to record everything, but since the incident happened right before Frank's turn to perform for the baby, Frank gives Greg credit for staging the whole thing.

The next morning, Frank reconsiders his decision to send Greg to Spag Union, which Greg perceives as being out of gratitude for saving him from embarrassing himself the previous day. Greg goes to Rowley's house, where they are greeted by their new neighbor, a girl their age named Trista. The book ends with Greg looking forward to his summer vacation.

The Last Straw received positive reviews. Positive attention was once again given to the character of Greg Heffley, with him being considered relatable.[2] The books' style of deadpan humor was also well received.[3]

On August 3, 2012, a film based on this book, The Last Straw, as well as the subsequent book, Dog Days, was released; the movie starred Zachary Gordon, Steve Zahn, Robert Capron, Devon Bostick, Rachael Harris, Peyton List, Grayson Russell and Karan Brar. Principal photography began on August 8, 2011 in Vancouver and was completed on October 7, 2011.[4] A poster was leaked in March 2012. A teaser trailer was attached to The Three Stooges.[5] An advance screening for the film was held on July 31, 2012.[6]