Two years after the bachelor party in Las Vegas, Phil, Stu, Alan, and Doug jet to Thailand for Stu's wedding. Stu's plan for a subdued pre-wedding brunch, however, goes seriously awry.

A veteran pot dealer creates a fake family as part of his plan to move a huge shipment of weed into the U.S. from Mexico.

A small group of former classmates organize an elaborate, annual game of tag that requires some to travel all over the country.

A 12-year-old boy searches for the one thing that will enable him to win the affection of the girl of his dreams. To find it he must discover the story of the Lorax, the grumpy yet charming creature who fights to protect his world.

Rusty Griswold takes his own family on a road trip to Walley World in order to spice things up with his wife and reconnect with his sons.

Two overly imaginative pranksters named George and Harold hypnotize their grumpy principal into thinking he's a ridiculously enthusiastic, incredibly dimwitted superhero named Captain Underpants.

A night debauchery in Las Vegas goes massively awry when three groomsmen lose their best friend during his bachelor party, just days before his impending wedding.

Two years after The Hangover Part II, Leslie Chow escapes from a maximum security prison, using a riot as cover. Meanwhile, in the United States, Alan Garner causes a multi-car freeway pileup after he purchases a giraffe and accidentally decapitates it on a low overpass. Alan's father Sid, angry with Alan for his immature antics and never owning up to his mistakes, dies of a heart attack in the middle of a lecture. After the funeral, Alan's brother-in-law Doug Billings informs friends Phil Wenneck and Stu Price that Alan has been off his Attention deficit hyperactivity disorder medication and is out of control. The group attends an intervention in which Alan agrees to visit a rehabilitation facility in Arizona where he can seek treatment, as long as "the Wolfpack" takes him there. On the way to Arizona, Phil's minivan is rammed off the road by a rental truck and the group is taken hostage. They are later confronted by mob boss Marshall and "Black Doug", his head enforcer.