Mission Responsible is the second episode of Season 6.
Cosmo and Wanda are exhausted from taking care of Poof, so Timmy volunteers to babysit and let them have a date night. The minute they poof away, Timmy loses Poof and must find him before Dark Laser can get a hold of him!
This synopsis needs improvement.
The story starts with Timmy reading his comic books when he was disturbed as Cosmo and Wanda passed by him at the speed of light. Timmy caught Wanda and said to her "boy trying to read comics here!" Then Wanda replied "fairy trying to change diapers here!" And then she goes inside their fishbowl. Then he caught Cosmo, who also goes inside the fishbowl. Timmy then sees Cosmo and Wanda very exhausted from taking care of Poof and suggests they go out on date night. Wanda then attempted to call Mama Cosma but Timmy suggested that he can babysit Poof. Wanda then objected and says "Just like you said you can take care of some other things around here?" They then viewed Timmy's dying pets. Timmy then replies "Hello you’re fairies, you can just poof back in here. It's like you'll be dining in the bathroom." Cosmo then says "huh? were dining in the bathroom? then I better learn how to use toilet paper!" (he smacks himself with it). He then promised that he’ll watch Poof and won’t take his eyes off of him for a second. Wanda accepts but she lends Timmy a fairy cellphone to call them if there’s any trouble. She then states all the things he must do and not do: shut the windows and do not watch violent tv. Cosmo then says "Your mission Timmy Turner is to be responsible and watch your fairy god brother. This message will self destruct in five seconds. one...yuh!"(he blows up) Timmy then replies "get out of here...have fun you cooky love birds and have a great time." Wanda answers "we're trusting you Timmy to keep an eye on Poof." Then they poof off.
At the restaurant, Wanda worries so much about poof and decides to call Timmy. Timmy answers the phone "responsible big brother here". Wanda then "oh huh, did cosmo dial the number and give it to me? Well, I have you, do you want to wish for anything, we can poof you something from here." Timmy replies "yes, I wish you would stop worrying and have fun with a conga line." Wanda then grants his wish and replies "that's sweet, call us if you need anything." Cosmo then get's mad "I knew it, your seeing a conga line of men with poofy sleeves!" Timmy then does the opposite of Wanda's reminders; he opens the window and turns on the TV, and says "This is called watching a movie you're not supposed to with the window wide open!" He then ends it with an evil laugh. And then he imitates Wanda "I can see it now! (in Wanda's voice) oh look, Poof is sleeping in Timmy's arms! You're so responsible Timmy. (back to his normal voice) and Cosmo will say (in Cosmo's voice) ow, ow, ow, (smacking his head like Cosmo did earlier), (back to normal) and I will say told you so, right Poof?" He then looks at the empty crib and screams in a panic that Poof is missing.
At the restaurant, Wanda keeps hearing things that remind her of Poof. She then calls Timmy who pretends everything is ok and imitates poof's snoring. Wanda replies "he's snoring pretty loud." He then sees a construction site and screams but tells them "ahhhhhhhhh, I mean OHH I just remembered I wanna warm up Poof's bottle before he wakes up and everything's fine bye!" He then goes to the construction site and goes to the level where Poof is playing. He almost caught him but he falls to a quick drying cement mix and hardens. Poof then poofs him back to normal. He then says "your lucky that it wasn't more dangerous. What are you doing?" He then poofs them to a much higher construction site. Timmy then says "can this be any more dangerous? " Poof then poofs a lion next to him. Timmy continues "I got to stop talking to that kid." He then falls off with the lion in a cement mix. He together with the lion hardened. He then gets malled by a wrecker and says "Ok, you had your fun, and we're safe, and the good news is, there are no more dangerous construction sites in the world. Why did I just say that?" Poof then poofs them to Dark Laser's Death Ball construction. Poof then accidentally goes inside the power supply of the machine. Timmy then destroys a tile which makes Dark laser furious and threatens to destroy the earth twice. Timmy then says "No, your world will be gone." He then jumps in another cement mix but with cover which hardens Dark Laser. He then removes poof and pushes to self-destruct button. The self-destruct initiation began and Timmy asks Poof to bring them home, but Poof can't understand this. Wanda then calls them "Coffees done, and we're coming home. Is there anything else?" While avoiding the debris, Timmy replies "no, up and up this stairs, warming bottles all night... and just poof as back to my room!" Wanda answers "you got it sport." Just in time, they poofed back to his room and Timmy watched the explosion. Timmy then says "we made it, I'm responsible...AHHHHHHHHHHH!....and I'm dead." Poof then cleans his room, and returns them back to normal. Then Cosmo and Wanda poof back, and Wanda is convinced that Timmy is responsible until the television suddenly opened and broadcasts "and tonight at ten more on the cute floating baby pink hatted kid in a high rise construction zone." Cosmo and Wanda then stare angrily at Timmy for disobeying them, and Timmy says "rattle time little bro." Then they're poofed to the destroyed ship of Dark Laser, and Dark Laser asks "do you know where I can get a deal on some Turkish new rugs?" Timmy replies "Don't talk, just fly." Then Dark Laser laughs as Flipsie flips. The foursome then travel into space as the episode ends.