Season 6
Operation: S.A.F.E.T.Y.
When a kid-friendly senator receives a funding of approximately eleventy-billion dollars, he uses it to build an army of Safety-Bots, to make the world a safe place for children. However, the robots grow more and more extreme in their actions, eventually planning to eliminate adults, and cover the Earth in bubble wrap.
Operation: E.N.G.L.A.N.D.
When Numbuh 1 is taken to England, someone gives him a book, resulting in Numbuh 1 getting followed by 3 kids.
Operation: A.W.A.R.D.S.
Sector V attempts to sabotage the Villain's Choice Awards.
Operation: R.E.C.E.S.S.
When salad oil is discovered in the school playground, Numbuh 1 must find a way to save recess, while still keeping a promise to Lizzie.
Operation: H.A.M.S.T.E.R.
While the team is off on their recess-rescuing mission, the hamsters are attacked and captured by the Sinister Felines from Atop the Litterbox, but end up battling the Hamsters Next Door.
Operation: W.H.I.T.E H.O.U.S.E.
Numbuh 1 wakes up to discover that he is the president of the United States in an alternate dimension, who is about to sign the Bill of No Rights for Kids.
Operation: S.P.I.N.A.C.H.
Amerigo Vespinaccio tries to spread spinach throughout the school, and Sector V must stop him.
Operation: M.E.S.S.A.G.E.
Numbuh 2 attempts to deliver the fourth grade president's message.
Operation: B.R.I.D.G.E.
Numbuh 20 000 and his Squid Squad work with Sector V to destroy the bridge leading into Le Sissie a store in the mall that sells horrible back-to-school clothes for kids.
Operation: S.I.X.
Numbuhs 2, 3, and 6 are tricked and must get a truckload of soda to a girl's birthday party and keep Mr. Fizz and Lieutenant Seltzer from getting the soda.
Operation: T.R.I.C.Y.C.L.E.
Tommy loves Numbuh 2's cruddy, old tricycle but gets laughed at when the other kids see him riding it. Using his 2x4 technology expertise, Tommy rebuilds it into the "Best Bike in the Whole World", but the bike turns evil trying to impress Numbuh 2.
Operation: C.R.I.M.E.
When Gallagher Elementary students are being arrested by the School Safety Patrol for crimes they are envisioned to commit, including detective Numbuh 2, leaving Numbuh 3 to investigate a psychic member of the School Safety Patrol while trying to finish her social studies homework.
Operation: P.A.R.T.Y.
With Father away at Saratoga Springs for the day on orders from his doctor, the DCFDTL invite Cree and the teenagers to their mansion to plan a new strategy against the Kids Next Door, but instead, the teenagers turn it into a wild house party, leaving the DCFDTL to call Sector V for help.
Operation D.O.G.H.O.U.S.E.
Numbuh 5 goes into the Haunted Doghouse to get Sector V's cinder block back, but later comes out with different results.
Operation: P.L.A.N.E.T.
Numbuhs 3 and 4 are launched into space to break the "Ridiculous" space barrier, but blackout in mid-flight and wake up on a world ruled by anthropomorphic, talking Rainbow Monkeys.
Operation: S.C.I.E.N.C.E.
This episode illustrates a day at the annual kids' 2x4 tech science fair. Numbuh 2 is present, shoving his "I Can't Believe It's Not Booger" product down the judges' throats.
Operation: A.M.I.S.H.
Continues from Operation: S.C.I.E.N.C.E.. When a mysterious enemy starts kidnapping KND scientists, Sector V sends Numbuh 2 into hiding at an Amish sector to his extreme dismay.
Operation: G.I.R.L.F.R.I.E.N.D.
Lizzie has always had to compete with the Kids Next Door for Nigel's attention, and she thinks Nigel has found a new girlfriend.
Operation: C.A.R.A.M.E.L.
Heinrich uses a ritual involving sacred golden caramels to take away the qualities the Sector V operatives value the most (Numbuh 1's leadership, Numbuh 2's intellect, Numbuh 3's giddiness, Numbuh 4's toughness, and Numbuh 5's coolness). Numbuh 5 eventually teaches Heinrich that he needs to share his candy to revert to his original form; finally learning to do, it is revealed that Heinrich is actually a girl named Henrietta, whose most precious quality, her femininity, was taken away in the ritual many years ago.
Operation: M.O.O.N.
Adults send Numbuh 4's family to the Moon to colonize it. However, Sector V diverts the colony to Hollywood, where they stage a fake colonization, tricking the Beetles family and the adults at mission control to prevent them from discovering the KND Moonbase.
Operation: T.R.E.A.T.Y.
The KND and the Teens are about to sign the "You don't mess with us-We don't mess with you" Kid-Teen treaty. It is going to be signed by Numbuh 8000 (KND and the Teens leader), but it turns out to be a trap for the KND, making Numbuhs 1 and 274 set out to prevent it after being falsely convicted by the KND.