All of the bathroom's stalls have been vandalized with red marker saying "Stainless."
Fillmore and Ingrid only have 48 hours to find the finished S.A.T.T.Y. 9 tests or else Ms. Folsom will make the entire student body retake it.
Fillmore doesn't trust Tony Clementina, when he takes the credit for the disappearance of the library's books. Meanwhile, Ingrid learns about Fillmore's past through an empty Carbee Cola can.
Time is running out for Safety Patrol, the Bocce ball team and Lobstee the lobster, the mascot. X's resident psychic, Alistair Greystone, has been called up for the job but is he real or just a fake?
Ingrid goes undercover as a Red Robin to catch the seemingly nice Girls Scouts as a strong arm team that attack competitors, steal candy and cheat in selling taffy. But will Ingrid find the stolen goods or will Ingrid become the new leader of the Red Robbins after Malika, the current leader, graduates?
Who sabotaged the Model Train Convention? The R/C Car Club, or was it an inside job?
It's up to Fillmore and Ingrid to find X's pride and joy, Duappy, the longest living virtual pet, before Duappy dies.
Fillmore gets a new partner, Brad Parnassus - the smartest kid X Middle School, after his old partner moves to Tennessee. Meanwhile, new student Ingrid Third tries to get used to X's student body.
Fillmore sleeps over in the school to safeguard Mrs. Cornwall's Pre-Algebra final exam, but a blizzard snows Fillmore in with a gang of exam thieves.
A field trip to the Modern Contemporary Natural History, Art, Science and Miniature Museum takes a turn when a mustache is drawn on the painting "The Lobster Man at Port" and it's up to Fillmore, Ingrid and O'Farrell find the culprit before it becomes permanent.
Fillmore and Ingrid go undercover to trace scooter thieves but they also face a challenge from B.A.G.A.S.T. (Boys And Girls Against Scooter Theft), created by Derek Minna.
X's best hope to break a losing record, Checkmatey, is being targeted, but who could it be? Could it be - Tyson Pelarez, leader of the society of the preservation of ethics in chess or is it Nelson Kelloch, Checkmatey's biggest rival?
Someone is out to get Fillmore and trying to frame him after student council rep Peabody gets a tip about bootleg hall passes in Fillmore's desk. Fillmore gets help from an old partner to figure out who it is, but will Fillmore go back to his old ways?
After the school's biggest Smoit stash is stolen, all of the evidence points to Toby, the Smoit co-owner. But is all as it seems?
All of the members of the Drama Club's projects are being shredded by a serial shredder. The Safety Patrol needs a profiler, so they seek out Frank Bishop, X Middle School's best and former profiler. After he joins, the evidence points to him, but Vallejo won't let the squad investigate it, since he's the reason Frank hasn't profiled since last year.
Linus Santiago refuses to tell the Safety Patrol how he made Dewey Hubble's robotic dog Barcode disappear because of the Magician's Code.
When Spring Break arrives, Fillmore visits his former partner, Wayne Liggett. In Wayne's new school, something about the Safety Patrol stinks. The prized pralines have gone missing and the prime suspect is Patrol Sheriff Thrift, who just so happens to be the son of their principal.
Winston Kotter, the Canadian ambassador, is staying over and has brought his assistant Penny Madrid, who is an old friend of Fillmore's. But Fillmore suspect's something is up when a huge supply of counterfeit baseball cards appear.
At the X Middle School Open, the professional golfers are failing at games, and foul play is suspected. Usually Fillmore is up for an undercover job, but Fillmore seems hesitate around the mini-golf tourney.
Rookie Officer Peter Chestnut has a lot to live up to when he is the last of his four brothers to join the Safety Patrol. When a shipment of stolen X Middle School foam spirit lobster claws is traced back to Oscar Mabini.
Torrey and Terri start to build projects to win the auditions to star in the next issue of Vampirita, a series of novels about an astronaut vampire, but all of them get sabotaged. The two main suspects TQ, a mysterious riddling talking type guy and Trace, a girl who never seems to be happy with the color of her hair, don't connect with the evidence, so who could have sabotaged the projects?
Fillmore and Ingrid must investigate the disappearance of a girl named Alexis.
Fillmore and Ingrid track down a gaming mastermind who stops at nothing to get an Ultrabox, the hottest new game system on the market. Fillmore and Ingrid think they have him but the Ultrabox is stolen while in custody, so it looks like they have a copycat on the loose.
Fillmore faces expulsion under Principal Folsom's new "Three Strikes, You're Out" rule.
The Safety Patrol are in a frenzy when four bullies - Rochelle, Bryan, Fiona and Horace, have been attacked and the four main suspects - Wilbur, Grover, Becca and Stella, who is bullied by each one, isn't proven to have had nothing to do with it.
Fillmore is given a license to go out and track down Eric Orben, the main suspect in poisoning Guildenstern, the Science Department's tarantula mascot, who has escaped into the city.