Diary of a Wimpy Kid: The Long Haul

After summer vacation starts, Greg's mother Susan announces that the family is going on a road trip. At a cheap low-end motel that night, Greg and Rodrick decide to go to the pool, but find that there is no water in it. There is a hot tub nearby, but it is occupied by a family and they cannot convince the family to let them use it. They return to their room to find that the rest of the family has fallen asleep, taking up the bed. Rodrick proceeds to make a bed for himself out of sofa cushions leaving Greg to sleep in the closet. He falls asleep for a few minutes before being woken up by kids who were playing with a cleaning cart. Greg yells at them for causing a commotion, making the smallest kid cry and call for his father, who nearly gets Greg. Greg nicknames the family the "Beardos".

The next day, the Heffleys go to a country fair, where Greg finds that the Beardos are there as well. Rodrick submits one of his shoes to the "foulest shoe competition" in the fair and wins, but doesn't get the shoe back. Manny wins a competition for guessing a hog's weight, but the prize was a piglet, which the Heffleys are forced to take with them. The family plans to spend the night at a hotel suite, but it has a strict no pet policy so Mom smuggles the baby pig in a cooler until the Heffleys reach their room. The pig ends up raiding the minibar, forcing the family to pay not only for the food and drinks consumed by the pig, but also an extra $50 for violating the hotel's no animal policy.

On their third day, Greg's dad Frank gets an emergency call from work. In the meantime, the family go to various places. While driving, Dad gets a call from one of his international clients, asking the family to stay quiet. But chaos ensues, Greg is bitten by the pig, and it attempts to escape, consequently ruining Frank's call. Infuriated, Frank ends up taking the pig to a petting zoo, which makes Manny very upset. Later Greg goes to a vet because of the pig bite. Manny tries to run away thrice and is forced to be on a leash. Soon it rains and Mom rethinks their road trip plans over. Mom convinces the rest of the family that because the trip was terrible so far, they will use a method of deciding which way to go for picking things, similar to how Choose Your Own Adventure works. The method works, but they get in hot water with a funeral procession.

On the fourth day, the Heffleys try to figure out where to go and Greg's mother chooses the beach, but on the way a seagull flies into their car through the open sunroof, and everyone freaks out. Rodrick, who is driving at that time, panics and steps on the gas pedal, rear-ends the car in front of them and break their car's radiator. The Heffleys car is towed to a mechanic's shop for repairs. Greg is surprised to see a water park that he was thinking about going to very close to them, but many misfortunes happen, and the family thought that their valuables were stolen by the Beardos Greg encountered at the hotel. The Heffleys call the police, but to no avail. Fortunately, their car keys were at the mechanic's and they go to the mechanic's to retrieve their car, but with their money presumed stolen, they cannot pay for the repairs. As a result, the mechanic uses sealant to temporarily fix the radiator. The drawback is that the car's heater has to run at full blast to prevent engine overheating.

While on the highway, a tarp covering Frank's boat loosens and the Heffleys' items begin falling out. They spend two hours trying to retrieve the contents, but many items are still missing. The family finds some loose cash in the car and buys nuggets from a fast food place for dinner. Then the family tries to find a place to sleep. Greg's father drives the car into the wilderness mistakenly believing that there was going to be a camping site in that area. The cinnamon rolls Rodrick had purchased previously, which were sitting on top of the car's operating heater vents (their car heater had to run at full blast due to the broken radiator), explodes, sending cinnamon bits onto the back of Rodrick's head. Rodrick panics thinking that the slime was his brains, and gets even more upset when Manny licks the stuff off his fingers. After a cleanup, the family finds a grocery store and parks in the parking lot for the night.

The next morning, the whole family accidentally lock themselves out of the car. They send Manny in from the open sunroof, but make a mistake when they remember that Manny had been trying to run away to find the piglet. After his attempt to drive the car fails, he lets them in. After a while, they find the motel where they spent their first night. They find the Beardos there again, and see them leave their room with their door unlocked. The family then enter the Beardos' room and rummage through their stuff, trying to find their own belongings, but find nothing belonging to them. Greg's dad decides to use the bathroom, while the family goes back to the car. Dad soon comes running out of the room and into their car with the Beardos' father hot on his heels. In the Heffleys' getaway, they forget to turn on the heater in their car, causing it to break down two miles down the road.

A car with two people pulls over and offers to help them. Greg's parents try to communicate with them, but discover that they can only speak Spanish. Luckily, to everyone's surprise, Manny speaks perfect Spanish to them and explains all the trouble on the trip, including the loss of his piglet. The two men give the Heffleys a ride back home, with a stop at the petting zoo to get Manny's piglet back.

After they arrive home, Greg's parents cancel their credit cards and purchase new phones. The boat is given to the brothers for their help much to Frank's dismay. While digging through his short pants pockets, Greg finds the key to their locker in the water park and is caught in a dilemma. He thinks that he is reading a page of the Choose Your Own Adventure books and can either tell his parents the truth, sabotage his brother Rodrick by putting the key in his brother's pants or flush it down the toilet and forget about everything that happened.