Act One: "Flushed Innocence"
The episode opens with Robin Spencer cutting the ribbon for a new girls' bathroom that had been made with high class materials. Robin leads a group of photographers and Principal Folsom into the bathrooms and gives a small speech before opening one of the stalls to show the new features only to find that the stall had "STAINLESS" written in red marker pen all over the walls, toilet and floor. Upon seeing this, Robin checks all the other stalls to find them in the same condition. Principal Folsom yells for someone to call the Safety Patrol immediately. The Safety Patrol arrive and rope off the bathroom, Fillmore and Ingrid arrive and find Tehama taking samples while O'Farrel took photos (nearly sending jets of water into Tehama's face by accidentally activating the toilets motion sensors) it was then revealed that the painting crew had finished the day before and propped open the door open all night for ventilation so anyone could have done it. Back at Safety Patrol Headquarters, Vallejo reveals that he wants to get this case solved before his fishing trip that weekend and asks for what clues they had. Anza reveals that the markers used came from the school and couldn't be traced while Tehama and O'Farrel had checked up on the list of known taggers and found no matches making the conclusion that it was a new offender. Ingrid suggests looking at the writing style to see if could be matched to a student, Fillmore then suggests showing the pictures to a Randall Julian to which the other members are tentative about but agree.
Randall Julian is a convicted student who is kept in indefinite detention in an isolated building on campus. Fillmore tells Ingrid the story that Julian was once a prize winning Macaroni collage artist but became a tagger to gain more notoriety who managed to tag every bathroom in the school except the one in the Teachers Lounge which Fillmore prevented him from doing by catching him. Upon reaching the building, a guard teacher asks the pair to hand over all writing utensils or anything that would allow Randall to write. Upon meeting Randall he shows little interest in helping them until Fillmore offers him the chance to be a macaroni artist again and states that stainless wrote from right to left rather than left to right.
Ingrid and Fillmore then go to Robin Spencer's office where Robin states that if the stalls had been brushed steel then ink wouldn't work on them but the committee refused them over expenses. Ingrid then discovers that when Robin's office had been put in, an art group had been thrown out and therefore may hold a grudge. Fillmore and Ingrid first visit the first of the three club members, Frankie Polk (the president of the club). Frankie told them that he found offices creatively confining. Tommy Howard (treasurer) a publicity seeking artist who was working on a black dot comprised of 700 coats of marker pen. And finally Jean Grace (recordings secretary) who states she is against indoor plumbing and had never stepped inside a school bathroom.
Meanwhile Tehama had made headway by revealing that one of the tags was faded revealing that the pen mush have sprung a leak and stained the hand of the culprit, leading the group to believe that whoever Stainless was, they would need a refill. Ingrid and Fillmore set up a stake out in the supply room and catch a hooded figure who snatches some markers, after a wild chase, the two catch the figure who is none other that Tommy Howard.
Act Two: "A Smearing of Justice"
Tommy is lead out of Safety Patrol HQ and confesses that he is Stainless in front of a group of student reporters. Vallejo returns to HQ to find a box waiting for him, think its the new fishing rod he ordered, he opens it only for fake fish to fly out and finds a mechanical fish singing "Row, Row, Row Your Boat" (backed up by the barber shop trio) causing all the others in the room to burst out into laughter. Fillmore then dampens the mood by stating that the markers were black where Stainless would be looking for red and there were no marks on Tommy's hands or wrists and that he wanted attention above all. Vallejo said that it was hard to believe that he would "smear his own name just to gets some attention", Ingrid then realizes what Randall had told them and shows Fillmore that the reason Stainless wrote from right to left was due to that they were left handed as writing from left to right would have caused the culprit to leave a smear of ink from the marker.
Fillmore and Ingrid return to see Randall who congratulates them on their find and the persuade him to help them further by offering him the access to art supplies under supervision. Randall reveals his reasoning for becoming "FLAVA SAVA" (his tagging name) and tells them which of the 17 new bathrooms was the most likely to be hit next, as the two leave, Fillmore's pencil falls from his back pocket and jams the door. Ingrid and Fillmore hold a stake out by the bathroom and catch Frankie Polk sneaking into the girls bathroom to draw pictures of the toilets. Fillmore advises him to draw in the boys bathroom next door, when the three enter, they are horrified to find "STAINLESS" written over the stall doors in large letters. Ingrid realizes that the ink was still wet but before they could do anything, a stall opens and a large jet of water sends the two flying. Although blinded by the water, Fillmore makes out a silhouette of someone climbing out the window.
Act Three: "Caught Red-Handed"
Principal Folsom emerges from Vallejo's office angrily telling him that she had to sign for Tommy Howard's release and for the payment of a huge shipment of brushed steel stalls and warns him that he had until 5 o'clock to solve the case or she would turn the Safety Patrol Headquarters into a Faculty Yoga Studio. Vallejo then orders Fillmore to go back to Randall for more advice however when they get there the guard bursts out of the building telling them that Randall had escaped. Fillmore and Ingrid enter Randall's cell to find the floor, walls and ceiling marked with "Flava Sava", Randall then appears on the close circuit television and tells them that he would make this school remember him no matter what and that he had left them a parting gift. On the desk in the cell they find an old copy of the school newspaper with a large photo of Robin Spencer cutting the ribbon of the stall. They then realize that in the photo, that she was cutting the ribbon with her left hand and she was wearing a glove on that hand.
In Robin's office, they find that Robin had applied for brushed steel stalls 43 times, all of them rejected until now. Fillmore states that what other way to prove that they were necessary than to deface the stalls herself, Ingrid then states that the new shipment was arriving at the loading dock at that very second.
At the loading dock, Robin is supervising the delivery of the stalls and admiring how much she had wanted them, she is then confronted by Fillmore and Ingrid. After distracting them by throwing the order forms at the pair, Robin flees into the stack of stall plating, bragging about how this was only the beginning Fillmore catches up to her. However, she pushes a stack of stalls onto one of them and runs for the exit. Fillmore dives into a mail cart pushed by Ingrid, which flies across the loading dock (smashing several boxes of Macaroni). In the cart, Fillmore finds Vallejo's fishing rod and uses it to pull a role of bubble wrap over Robin who falls and is unable to free herself, Fillmore then jumps from the cart as it is about to fly out of the loading dock opening. Meanwhile, Tehama and O'Farrel arrive and arrest Robin.
At HQ, Vallejo tells Fillmore and Ingrid that Folsom isn't sure whether to congratulate or punish them as they managed to catch the crook however they also destroyed a fortunes worth of equipment and allowed Randall Julian to escape. In the Teachers Lounge, Randell takes out a marker and is about to start work on tagging the stalls when Fillmore appears and manages to convince Randall that his old macaroni work is more appreciated than his criminal Flava Sava alias. Randall drops the marker and leaves with Fillmore. The episode ends with Randall asking if Fillmore knew anywhere where he could find some macaroni, to which Fillmore happily replies that he does.
- Parodied crimes: Vandalism/Serial killer
- When Fillmore and Ingrid were looking up on Randall's history, two newspaper headlines depicting crimes from unaired episodes appear.
- Randall Julian's character is based on Hannibal Lecter from the movie The Silence of the Lambs.