The Wrigley family goes on their yearly trip to Hoover Dam. When the family stops to eat for lunch, another man and his family also stop off at the same place, on their way to the Hoover Dam. Dad is determined to beat the other father for the title 'King of the Road'. The outcome? A bunch of naked Wrigleys.
Ellen is chosen to be the dot of the 'I' in the upcoming band performance. After spending more time with her partner than Pete, Pete gets jealous.
Pete is mad at his Mom about his bed time.So he, Artie, and other friends attempt to brake the world record of how many days can you go without sleeping. Only one kid will survive with help from the person he is mad at in the first place.
Older Pete gets a job as a rangeboy at the driving range that Mr. Wrigley frequents. Meanwhile, Artie becomes friends with Clark the turtle again.
Older Pete tries to get a C in his shop class by making the most average thing that he can. His plan fails when his shop teacher, Mr. Slurm, makes him work on his special project with Endless Mike.
While younger Pete has a hard time in gym class, older Pete finds out that he forgot about a test on the Revolutionary War.
While Grandpa visits, both Petes fight over who can have Mr. Wrigley's prized bowling ball, Rolling Thunder. Meanwhile, Mr. Wrigley works on a new finger excersize program to try and get his fingers back in shape to be able to fit back into Rolling Thunder.
Younger Pete stumbles across a band practicing in a garage. He loves the song that they're playing, but then forgets how it goes. He forms his own band and tries to re-create the song.
Little Pete destroys Dad's lawn in an experiment gone awry, and is forced to tunnel his way out of the house past a state-of-the-art security system in order to make it to the celebrations of his favorite holiday, the Fourth of July. Pete meets Nona F. Mecklenberg (Michelle Trachtenberg), whose father is played by rock star Iggy Pop.
Big Pete's baseball team (The Prosthetics) goes on a winning streak due to Little Pete's incredible knack for making distracting comments. Coach Ed Narrons' win-or-die attitude, a super-cold slushy drink called the Orange Lazarus, and Little Pete's dirty tactics threaten to destroy baseball forever, and Big Pete must choose between ultimate glory and the personal integrity of the sport he loves.
On the hottest day of the summer, Little Pete decides to answer an infamous pay phone that has been ringing for twenty-seven years, while Big Pete decides to figure out who the call is for.
Little Pete copes with the death of his pet lizard Gary while Big Pete struggles to improve his relationship with Dad in hopes of avoiding a lifetime of awkward conversations.
On the day that Daylight Saving Time ends in the fall, the Petes celebrate the extra hour by taking advantage of the "time warp" to do something momentous. This year, however, Big Pete is overcome by hormones and asks Ellen out on an official date. He enlists the help of his nemesis, "Endless" Mike Hellstrom, to help the date go smoothly. Mike lends Big Pete his customized Ford Mustang convertible and teaches him the nuances of dating. When things don't work out right, Big Pete is forced to use the power of the time warp to fix things with Ellen before their friendship is lost forever.
Little Pete finds his guardian angel, Inspector 34, who inspects the Kreb of the Loom underwear worn by the Wrigleys and their friends. While Inspector 34 recruits Little Pete to be an inspector, Pete shows him how to interact with normal people and have fun. Little Pete struggles with perfection while Inspector 34 lets his tendency toward perfection and his hormones go to his head. The new-found perfection of Inspector 34 begins to infect the neighborhood, and people begin behaving erratically. Little Pete must help everyone find a way to live in moderation between perfection and abnormality.
Little Pete decides to enter the annals of history by breaking the record for most houses visited on Halloween and tries to enlist the help of Big Pete. Big Pete is torn between his loyalty to his brother and the coming of age and abandonment of the childhood ritual of trick-or-treating. He must decide whether to face the ridicule of his peers and go trick-or-treating or to join the notorious "Pumpkin Eaters", a group of vandals who terrorize neighborhood "Halloweenies."
Ellen, fed up with algebra word problems, asks the question high school teachers dread most: "Why (do we have to know this)?" Her inquiry spreads like wildfire throughout the school and soon students are rebelling against the textbook knowledge forced upon them in every class. Ellen realizes that things have gone too far when math teacher Ms. Fingerwood disappears, and she desperately tries to put things right.
The Wrigley family takes a fishing trip, and Big Pete contemplates mortality while Dad tries to catch a legendary fish named Bob. Also, after realizing the cruel fate that could happen to Bob, Big Pete tries to sabotage Dad's attempts on making the catch.
The end of Artie's influence over Wellsville comes in two parts. Supervillain John McFlemp (James Rebhorn), head of the International Adult Conspiracy, concocts a dastardly plan to rid the Wellsville parents of the nuisance that is Artie forever, and threatens to destroy all that is unique about the kids of Wellsville. McFlemp extorts Dad and convinces him to get rid of Artie. Meanwhile, Pete is being harassed by his own villan, Paper Cut, who uses paper folded into origami-like shapes as weapons.
The Petes, Ellen, and Little Pete's various friends start a campaign to find Artie, who disappears in Dad's car after a disheartening speech from Don (Dad). The campaign consists of a Bat-Signal-esque likeness of Artie's face, t-shirts, and various souvenir items. After Dad realizes his mistake and joins in the search, Artie is brought back to Wellsville, only to find Little Pete standing up to Papercut on his own, demonstrating that Artie's protective influence is no longer needed. A tearful departure follows as Artie leaves in search of another little boy in need of a superhero.
Big Pete is stuck on a school bus departing for the deepest, darkest parts of the human psyche, as well as the county milk museum. During the bus ride, Pete befriends people he never thought he'd associate with, succumbs to the temptations of bullying, and is forced to cope with his actions and repent.
Little Pete decides to fake food poisoning in order to avoid another mind-numbing day at school during the stretch between winter and spring break. In an adventure that leads him from home to school and the various sites around Wellsville, Little Pete sees a classmate of his in a new light, gets a cereal marshmallow-likeness of President Dwight D. Eisenhower stuck in his nose, and gains a new perspective on the world that can only be appreciated on a sick day.
