|Season 6, Episode 13a|
|Air date||October 24, 2007|
Operation: H.A.P.P.Y. is an episode from the sixth season.
In the recess, Numbuh 1 asks Numbuh 3 where Numbuh 5 is. She says Numbuh 5 is at a karate convention for a couple of days. Numbuh 2 comes and says that Numbuh 4 is acting pretty weird. Just then, Numbuh 4 comes along with an eerily blank smile on his face and asks if it's a happy day. He says that he watched a show called "The Happy Show Show" and that it's in channel three hundred and fifty-seven and that it will make him "happy". Sheen then walks away. Instead of watching the show, Numbuh 1 does things on his computer, including looking at images of his crush Lizzie, until Numbuh 4 keeps bothering him to watch the show by saying "You could watch it the next day... or the next day... or maybe the next day!".
Numbuh 1 keeps ignoring Numbuh 4 and finds himself at school, where he is terrified when Numbuh 2 comes up to him and asks if he watched "The Happy Show Show" last night. Numbuh 1 doesn't answer, looks and sees Butch and Bolbi being friendly to each other as they walk in. Numbuh 1 sees Numbuh 3 turn off some music, which is extremely unlike her. She asks him the same question, another unheard-of occurrence and everyone is acting creepy and strange with eerily blank smiles.
Lizzie also tells him he should watch the show, and so he decides to. That night Numbuh 1 turns to the channel to find a show made by a woman named "Grandma Taters". He becomes flabbergasted as he watches only the first 10 seconds and turns the show off and hates it in disbelief. He goes to school the next day and all the kids start to insist that he watch the show again, displaying increasingly alarming behavior.
After arguing long enough, Lizzie says that he could watch it with her at her house, which convinces Numbuh 1 to give it a second try. Numbuh 1 goes over to Lizzie's and stops outside. He happens to look through the window and see the show on a mirror. As he watches the show via the window, the plot thickens as he sees the show using hypnosis to turn everyone watching it in Retroville (but soon the entire world) into mindless happy zombies. Numbuh 1 is shcoked to see this and runs into Lizzie's house and tries to tell her to stop watching the show but she says must watch and he must watch too while giving him a bit of an evil smile prompting Jimmy to leave her house screaming. Numbuh 1 runs home and tries to tell Monty and Mrs. Uno about the show and they should call someone about it only to find out that they’ve been effected by the show too. He runs out of his house into town and is surrounded by mindless happy zombies.
Numbuh 1 crashes into Numbuh 5, who had just returned from her karate convention and she angrily pushes him off her, telling him to watch where he’s going. Numbuh 5 says she's sad that she is filthy and lost at the karate competition, but Numbuh 1 is glad that she's not "happy". Numbuh 5 misunderstands this, but Numbuh 1 tries to explain what has happened she doesn’t quite understand him. When the zombies show up to get Numbuh 1, they see that Numbuh 5 hasn’t been watching the show either and they chase Numbuh 1 and 5 as they fortunately are able to escape. Though she listened, what Numbuh 5 got the most out of the conversation is that Numbuh 1 had gone over to Lizzie's house.
After Numbuh 1 finds where Grandma Taters is, Numbuh 5 asks what he was doing at Lizzie's house and Numbuh 1 lies by saying it was for research. They head for Grandma Taters' house to stop her worldwide broadcast. After confronting the woman, she whistles where Numbuh 1's friends capture him and tie him to a chair so that Taters can broadcast. Numbuh 5 enters, seemingly hypnotized but soon reveals that it's a ploy as she fights the zombies and Taters with her karate.
With Taters and the zombies subdued, Numbuh 1 dresses as Grandma Taters and restores their minds. Numbuh 1 tells Taters that even though she meant well, she shouldn't mess with people's minds. She agrees that it was a bad idea, but then a UFO lands and three copies of Taters come out to greet her. She leaves with them, but not before ominously saying "We'll be back!" while showing her true eyes out from under her glasses which frightens Numbuh 1 and 5. After this, Numbuh 5 once again asked what Numbuh 1 was doing at Lizzie's house after which they argue about it.
- Numbuh 5 lost the competition to a six year old beige belt on crutches. In Operation:, we learn that Sheen has a beige belt in Ultra Lord poking and pinching. In other words, she lost to someone in Sheen's level of fighting ability.
- We learn that Numbuh 1 and 2 have known each other for five years.
- This is the only episode to feature internal monologue.
- This is also the only episode to have Numbuh 1 as the narrator.
- Although this episode was released in 2007, you can actually see "Copyright 2003 Viacom International, Inc." at the end of the credits. This means that the episode was produced in 2003.
- Numbuh 4 insisting Numbuh 1 to watch "The Happy Show Show" the next day so many times is a reference to "The Algae's Always Greener", an episode from Season 3 of SpongeBob SquarePants.
- When Grandma Taters tells Numbuh 1 and 5 that she'll be back, it is a reference to The Terminator.
- The name is a reference to the climax of the film Freaks.