Matthias "Matt" Lee Whitlock (Denzel Washington) is the respected Chief of Police of the fictional small town of Banyan Key, Florida. He has recently executed a successful, high-profile drug bust that turned up $450,000 in drug money.
The film opens on a stormy Alabama beach with two children, Melanie Smooter and Jake Perry, chasing each other. Jake has brought Melanie out to show her the glass sculptures that result when sand is struck by lightning. They discuss their future together, with Jake asserting they will be married one day. They kiss and are almost struck by lightning.
Dave Goodman (Devon Sawa), Sam Schecter (Jason Segel), and Jeff Davis (Michael Maronna) are best friends who have spent almost four years at Holden University scamming their way through college. During one exam scam in their final semester Dave discovers Angela (Jaime King, credited as James King), and asks her out while writing his phone number on her exam sheet. Ethan Dulles (who calls himself "Cool Ethan") (Jason Schwartzman), a classmate obsessed with Angela to the extent of collecting loose hairs and making a hair doll and having surveillance photos and a shrine to Angela setup in his dorm room, takes her exam question sheet after Angela leaves and uses it to repeatedly confront and then blackmail the guys into setting up a successful date with Angela for him in exchange for his silence on the matter. The guys set Ethan up in multiple situations in an attempt to convince Angela to like him, while Dave tells Sam during their work researching her that Angela is no more important to him as any other scam they've done. Ethan fails to attract her after frequent confrontations based on his delusional behavior, immaturity and ignorance of social norms.
An NSA mission to collect intel on Anarchy 99, a mercenary group made up of former Russian soldiers goes awry when the agent's identity is discovered by the group. NSA Agent Augustus Gibbons, overseeing the operation to get any intel on the group's plans for the biochemical weapon named "Silent Night" that has been missing since the fall of the Soviet Union, believes the only way to get close is to recruit an agent that would not have any ties to the United States government. He selects Xander Cage, also known as X, an extreme sports professional and host of his own television show who is outspoken against the government and was recently captured by the FBI for stealing and destroying a prominent California senator's car as an act of protest. Gibbons puts Cage through two tests - stopping a staged diner robbery, and escaping from a drug cartel's plantation in Colombia - and offers Cage the mission. Cage reluctantly agrees when Gibbons offers to wipe his criminal record away.
Picking up several years after the first film, Ryan Sommers (Robin Dunne) is a student at an unnamed university, believed to be Yale University by the sports teams logo and various New Haven, Connecticut, imagery seen throughout the film. He and lacrosse teammate, Jeff, are tapped for the elite "Skulls" society. Despite his friend Jeff's zeal for being tapped, Ryan is ambivalent toward admission into the Skulls seeing it as a form of control from his older brother, Greg (who is a member), and its distraction from his beautiful, socialite girlfriend, Ali (Ashley Tesoro).
On docks outside Los Angeles, a semi-truck is loaded with electronics, but a corrupted dock worker informs an unknown person about the truck shipment. During the night, while the truck drives on the interstate, it is approached by three heavily modified black Honda Civics with green underglow. The occupants of the Civics immobilize the truck driver, hijack the truck and escape, passing through a roadblock and stealing thousands of dollars worth of shipment.
Sixteen-year-old Ruby (Leelee Sobieski) and 11-year-old Rhett (Morgan) lose their parents in a car accident. Their parents' will is not a recent one but, in accordance with its terms, the children are placed under the guardianship of family neighbors from some years back, the childless couple Erin (Diane Lane) and Terry (Stellan Skarsgård) Glass, who live in a large glass house in Malibu.
In the stereotypical high school community of John Hughes High in Southern California, sexy Priscilla (Jaime Pressly), a popular cheerleader, separates from her football star boyfriend, Jake Wyler (Chris Evans). After Jake discovers that Priscilla is now dating peculiar Les (Riley Smith) just to spite him, one of Jake's friends, Austin (Eric Christian Olsen), suggests seeking retribution by turning Janey Briggs (Chyler Leigh), a "uniquely rebellious girl", into the prom queen.
Darren Silverman, Wayne LeFessier, and J.D. McNugent, best friends since fifth grade and Neil Diamond fans throughout, form a Neil Diamond tribute band called "Diamonds in the Rough". Darren meets a beautiful but domineering psychologist who is showing signs of being emotionally abusive , Judith Fessbeggler, through a chance encounter in a local bar after a band gig. Unfortunately, six weeks into their relationship, Judith is still making Darren watch her change clothes, and though sleeping together is satisfying for her, Darren gets nothing but a sore jaw. Judith isolates Darren from his friends, demands that Darren quit the band, receive humiliating medical procedures, and attend relationship counseling under her care. Wayne and J.D. decide to save Darren from her by attempting to bribe her, arm wrestle her, and shock her with faked photographs of Darren cheating, all to no avail.
Cassie and Sean, as well as ex-boyfriend Matt and good friend Annabel, go to a club situated in an old church. There Cassie sees a man with a clear, plastic mask (Carl Paoli) and an imposing man with a scarred face (Ken Moreno). Deathmask tries to grab her on the dance floor, but she pushes him away and steps outside the club with Sean.
The film opens with Sebastian Valmont (Robin Dunne) conversing with his soon-to-be ex-principal and the principal's insistence on having Sebastian's permanent record relayed to his new school, thereby hampering his chance for a new start at Manchester prep. Following his arrival in New York, Sebastian discovers the wealth of his new family; meeting Kathryn Merteuil (Amy Adams) for the first time and bettering her with piano and vocabulary. This leads to a confrontation between Kathryn and Sebastian whereby she states that she has a comfortable lifestyle and that he "better not interfere".
While on a road trip in the Southwest, Rae (Long) discovers that her man, Michael (Foxx), spent the $15,000 they set aside for a home on a vintage Studebaker. Rae promptly dumps Michael at a convenience store and hops a ride to the airport. Soon after, Michael loses the car when a young kid cons him out of the keys.
Luke McNamara (Joshua Jackson) is a student with aspirations to become a lawyer. A "townie" who grew up on the "wrong side of the tracks", he did well enough in school to attend college on a scholarship where he is a champion rower. His best friends at college are his love interest Chloe (Leslie Bibb), and Will (Hill Harper) who is the coxswain of the Bulldog 8's rowing team of which Luke is the captain (at the victory party for the 8's, Chloe is revealed to come from a wealthy family which is why Luke is reluctant to reveal his feelings for her). Luke's friendships hit the rocks when he is invited to join a secret society known as "The Skulls". After Luke passes the first part of the initiation process - theft from a rival frat together with boxing prodigy Caleb Mandrake (Paul Walker) as his co-conspirator and alleged "soulmate", and being lectured in the secret ritual room by a senior Skull that is standing in front of a wall with the word "WAR" engraved into it in huge capital letters. A senior Skull explains to Luke that the Skulls require their members to prove themselves in war. Luke has a falling out with Will when the latter realizes that Luke has become a Skull.
Amy Mayfield (Jennifer Morrison) is unsure about her thesis. But after a conversation with security guard Reese Wilson (Loretta Devine), she decides to make a film about a serial killer murdering in the fashion of urban legends.
In an upscale New York City mansion, wealthy and popular Kathryn Merteuil (Gellar) is discussing her prep school with Mrs. Caldwell (Christine Baranski) and Caldwell's daughter Cecile (Selma Blair). Kathryn promises Mrs. Caldwell that she will look out for the sheltered and naive Cecile. Sebastian (Phillippe) enters and Mrs. Caldwell reacts to him coldly and leaves with Cecile. Kathryn reveals that her real intention is to use Cecile to take revenge on Court, her ex-lover, who had dumped her for Cecile. Kathryn asks her step-brother Sebastian to seduce Cecile; he refuses as he is planning to seduce virgin Annette Hargrove (Witherspoon), the daughter of their school's headmaster. Annette is a 'paradigm of chastity and virtue' who recently wrote a published essay about saving herself for marriage and has been temporarily staying with Sebastian's aunt. The two make a wager: If Kathryn wins, she gets Sebastian's vintage Jaguar XK140; if Sebastian wins, Kathryn will have sex with him. It is mentioned that Sebastian keeps a journal detailing his conquests.