After 18 months in jail, our Trailer Park Boys, Ricky and Julian , head back home to Sunnyvale Trailer Park aiming to get their lives back together again. The problem is that neither Ricky's fiancee Lucy nor his dad Ray will let him back into their homes, and some guy named Cyrus has moved into Julian's trailer, having crowned himself the new "King of the Park."
Fed up with all their demands and complaints, Julian tells everyone that he is leaving the trailer park. Ricky, who has been living in Julian's car on his front lawn, has one week to find a new place to live. Mr. Lahey, the trailer park supervisor, is thrilled to hear of Julian's imminent departure but when he hears that Ricky won't be leaving too, his worst nightmare seems about to come true.
In desperate need of $2,000 to buy some hydroponics gear for his dope-growing business, Ricky reluctantly agrees to star in one of J-Rock's amateur porn films to be shot in J-Rock's trailer. Ricky, however, isn't quite up to the task, and the video, entitled "From Russia With The Love Bone", eventually winds up in Mr. Lahey's possession. Julian must convince Lahey that using the tape against Ricky would not be in Lahey's best interest.
While babysitting both Trinity and Mrs. Peterson's dog, Ricky accidentally gets shot and the dog devours a tray of hash brownies. A vet treats both the dog and Ricky. In order to pay the vet, Ricky and Julian must repossess a lawn tractor owned by a former patient who hasn't paid the vet's bill. The Boys successfully recover the tractor -- but not before Ricky gets shot for the second time that day.
With Ricky's life still a mess, Julian tries to convince him that it's time to marry Lucy. Reluctant at first, Ricky changes his mind when Julian suggests that people will always think that Ricky is gay unless he marries Lucy. Julian's engagement present to Ricky is the '76 New Yorker, which for weeks was up on blocks in his front yard, and is now made operational thanks to a few purloined replacement parts.
Lucy insists that Julian take over the job of organizing her wedding: which is odd since Julian isn't the groom, Ricky is. She wants lots of people and lots of food. The people part will be easy but getting that much food will be difficult on a tight budget. Julian's plan to hit a local grocery store runs into a snag when Ricky unexpectedly shows up in the middle of the heist. Shots are fired. The next day, the cops show up uninvited to the wedding.
The boys get arrested for robbing an ATM machine and spend 18 months in jail. When they get out, they decide to pull off "The Big Dirty" which is to steal a large amount of coins and quit their life of crime forever. This is a cinematic movie and is not filmed in the familiar mockumentary format of the TV series.
The time is one year after the boys successful "Train Scam" on the Maine border. Since then, Julian has insisted that they lay low and not spend any of the money, but the time finally comes that the gang will get their cut of the job. However, the boys and their money are soon parted and they are broke again, and now that they are penniless they have to deal with Lahey who has a brilliant new plan to evict them from Sunnyvale forever.
Ricky, Julian and Bubbles are about to get out of jail, and this time, Julian vows to go straight, even open a legit business. Soon the Boys will all be rich. At least that's what they've told the parole board. But when they arrive back at the park, they find it's not the same old Sunnyvale - and it's not the same old Jim Lahey, Trailer Park Supervisor. Lahey's a new man, hasn't had a drink for two years. And he has plans - BIG PLANS - for Sunnyvale. But unfortunately for Lahey, Julian stands in his way. With his big plans for Sunnyvale going down the toilet, his relationship with Randy broken down, and having the Boys back in the park is all way too much pressure for him to bear. For Jim Lahey, the countdown to liquor day is on. Meanwhile, Julian's having problems of his own and the Boys are forced to resort to doing what they know best - breaking the law. Lahey's descent into the liquor coupled with the Boys descent into crime puts them all on a collision course to mayhem and destruction.
Recently out of jail and completely broke, Julian has a plan to get outrageously rich. However, he first has to deliver his product to Montreal where his rival Cyrus is waiting to close the deal. In the meantime, the government's plan to legalize marijuana threatens Ricky and his dope business, so he goes to Ottawa to take action against the impending bill. With Julian and Ricky on a road trip, Bubbles joins the pair with his own agenda - to go find the inheritance left for him by his long-lost parents. The trio runs into trouble when ex-park supervisor Jim Lahey and Randy go after the boys in hopes of making them rot in jail.