In "Operation: S.A.F.E.T.Y. (Senator Attacks Foes Endangering Today's Youth)", a senator spends eleventy billion dollars to create an army of gigantic robots that set out to encase anything that they feel is dangerous to kids in bubblewrap. Things quickly get out of hand when they realize that pretty much anything could potentially be harmful to kids, including adults! The senator finds himself forced to team up with the Kids Next Door to destroy his creations.

In "Operation: R.E.C.E.S.S. (Recreation Ended 'Cuz Enemies Savor Salad)", salad oil is discovered under the playground at Gallagher Elementary. Principal Sauerbraten takes advantage of this find, making students work to pump the oil out during recess so it can be marketed. The Kids Next Door plan to strike back, but their plans interfere with the date Numbuh 1 promised his girlfriend, Lizzie. In "Operation: H.A.M.S.T.E.R. (Hungry Archenemy Meowers Strike To Entrap Rodents)", while the Kids Next Door go off on their mission to save recess, the hamsters of the Treehouse...

In "Operation: W.H.I.T.E.H.O.U.S.E. (What Happens If The Existing Head Of United States Escapes)", Numbuh 1 wakes up to find himself an adult and the President of the United States! And not only that, his government is trying to force him to sign the 'Bill of No Rights for Kids', which would mean the end of the Kids Next Door. Now Numbuh 1 must win the trust of the current Kids Next Door, led by his own son, so together they can stop the government's plans and figure out a way for him to get home.

In "Operation: W.H.I.T.E.H.O.U.S.E. (What Happens If The Existing Head Of United States Escapes)", Numbuh 1 wakes up to find himself an adult and the President of the United States! And not only that, his government is trying to force him to sign the 'Bill of No Rights for Kids', which would mean the end of the Kids Next Door. Now Numbuh 1 must win the trust of the current Kids Next Door, led by his own son, so together they can stop the government's plans and figure out a way for him to get home.

In "Operation: S.P.I.N.A.C.H. (Salad Pushing Invaders Now Attempt Crusade Here)", the Spinach Armada arrives at Gallagher Elementary. These invaders have been sent from a foreign land on a mission to force kids to eat spinach. The Kids Next Door, of course, refuse to let them succeed, but it appears one operative actually likes spinach and might not be so willing to help his teammates. In "Operation: M.E.S.S.A.G.E. (Make Express Shipment Speedily Avoiding Gummy Enemies)", Numbuh 2 is given an important message to be delivered through the Kids Next Door's Baloney ...

In "Operation: S.P.I.N.A.C.H. (Salad Pushing Invaders Now Attempt Crusade Here)", the Spinach Armada arrives at Gallagher Elementary. These invaders have been sent from a foreign land on a mission to force kids to eat spinach. The Kids Next Door, of course, refuse to let them succeed, but it appears one operative actually likes spinach and might not be so willing to help his teammates. In "Operation: M.E.S.S.A.G.E. (Make Express Shipment Speedily Avoiding Gummy Enemies)", Numbuh 2 is given an important message to be delivered through the Kids Next Door's Baloney ...

In "Operation: B.R.I.D.G.E. (Before Really Incredible Destruction Gotta Evacuate)", the Kids Next Door are on a mission to destroy a bridge in the mall that leads to a store where parents buy ridiculous-looking clothing for their kids. When Numbuh 5 discovers a group of kids living in the store who refuse to leave because "good clothes come to those who wait," the Kids Next Door have to find some way of convincing them to evacuate, because the bridge is going to blow up very soon. In "Operation: S.I.X. (Soda Is X-changed)", a mysterious girl approaches Numbuh 2 and ...

In "Operation: T.R.I.C.Y.C.L.E. (Tommy's Ride Is Calamity You Can't Let Escape)", Tommy finds Numbuh 2's old tricycle while cleaning out the garage and decides to make it his Tommymobile. The other kids mock him when they see him riding it, so he uses his 2x4 technology skills to improve the Tommymobile. But in so doing he inadvertently turns it into a monster tricycle on a mission to destroy all the other kids' bikes... and the Global KND Central Bicycle Command Hub if the Kids Next Door don't stop it soon!

In "Operation: C.R.I.M.E. (Crayon Renderings Implicate Mostly Everyone)", students at Gallagher Elementary keep getting thrown in detention for crimes they are supposedly going to commit in the future. When even the school's resident detective, Numbuh 2, is arrested, it's up to Numbuh 3 to do his job and discover what's going on... and at the same time get some advice on coloring the map of the United States that she's working on for a school project. In "Operation: P.A.R.T.Y. (Party Animals Rule Teens Yell)", the Delightful Children From Down the Lane invite the ...

Operation D.O.G.H.O.U.S.E: Numbuh 4 tries to find where his disappearing homework goes to. Operation P.L.A.N.E.T: Numbuhs 3 and 4 crash on an alien planet run by Rainbow Monkeys.

Lizzie's always had to compete with the Kids Next Door for Nigel's attention, but now it seems she has a rival for his love! What kind of person would do such a thing?!

Operation S.C.I.E.N.C.E: The latest 'fantastical', 'amazifying' and 'tree-mendous' treehouse upgrades. Operation A.M.I.S.H: The gang race against time to recover KND scientists.

Numbuh 4's family are sent to colonize the Moon, but the KND divert them.../Heinrich uses sacred golden caramels to take away the qualities the Sector V operatives most value.

"Operation: T.R.E.A.T.Y." (Teens Readily Enact Armistice To Youngsters) In a surprise move, the teens offer a historic truce to the Kids Next Door organization, but the peace process is threatened when things turn out to be not what they appear. Is the powerful KND diplomat a member of the splinter cell with designs on ruining the treaty negotiations?! Does the teen arch enemy Chad have a plan of his own?! When Nigel is suspected of treason, arrested and handcuffed to Chad, can they work together to save the future of the Kids Next Door?!

"Operation: I.N.T.E.R.V.I.E.W.S." (It's Now The Extra Really Very Interesting End Wrap-up Story) In a series of interviews with the KND after they're all grown up, the former operatives are temporarily brought out of their decommissioned haze to discuss what happened during their very last mission with Numbuh one - where he disappeared and was never heard from again! It all started with a routine mission to get the Delightful Children's birthday cake, but when a mysterious boy steals it instead, he makes it available to whoever wants it, IF they can solve his 'simple'...