Stitch is running through trees while trying to hide as Lilo had finished counting. While looking around to find Stitch, she eventually finds him in the palm tree. Lilo is not pleased by this, as Stitch was supposed to hide instead of telling her where he is, thus defeating the purpose of hide-and-seek. Suddenly, an aircraft has abducted Stitch from the tree, and Lilo goes after it but soon loses it.
Back at her house, Jumba finds Pleakley in the living room looking at some magazines, which he refers to them as his "treasure of Earth knowledge." Lilo soon returns back home and tells them of Stitch's disappearance. She then suggests using Jumba's ship to find him. Jumba tells her that his ship is not working, so Lilo decides to rescue Stitch on her own. Jumba warns her that she cannot go on dangerous missions without 626.
Lilo wonders who could do the job better than her until Pleakley finds a magazine cover of Kim Possible. He then tells Lilo that they can go to Kim's website, tell her that they are in trouble, and take advantage of her highly efficient secret agent skills. Jumba then looks at the magazine which soon intrigues him, regarding Kim's impressive resume. Lilo is pessimistic about having to hire Kim and claims she does not need her, as they can do the job themselves. However, Pleakley assures Lilo that the "saving business" should be left to the professionals, as he soon writes an e-mail to Kim reading: "ATTENTION! URGENT MATTER, SAFETY OF THE WORLD AT STAKE, NEED HELP A.S.A.P." and sends the letter. Pleakley then says that they will have to wait for Kim to arrive, though Lilo is worried if Stitch needs them right now.
When Kim, Ron Stoppable, and Rufus arrive to help Lilo save Stitch, Jumba notices Ron's pet naked mole rat. He mistakes Rufus for Experiment 607 (Launch) and chases him for most of the adventure, much to Ron's horror.
Meanwhile, Dr. Drakken and Shego have Stitch confined inside an underwater base, where they both prepare to clone him. When Kim goes out to find the base and rescue Stitch, she gets sucked into a current ("People Eater") and is also taken hostage. Eventually, Stitch and Kim are rescued from their prison by Lilo and Rufus. Everyone then manages to escape the underwater base.
Back on the beach, Jumba is still convinced that Rufus is Experiment 607. However, Stitch takes Ron's pet naked mole rat, sniffs him a few times, and reveals to Jumba that Rufus is not one of his "cousins" but a mole rat, much to Jumba's surprise. Later, Lilo teaches Kim how to dance the hula, and everyone has a good time together.
Moral: Never doubt others based on what they look like or who they are.
This is the first crossover episode in production order.
Jumba's concerns about Rufus being Experiment 607 were ironic. As seen in A Sitch in Time, Rufus had 3000 hyper-evolved descendants in that timeline. Their apparent leader, Rufus 3000, was armed with multiple chronal manipulators and considered Rufus his superior. So Rufus actually was in a position to drastically impact the time stream, he just never took advantage of it. He easily could have done just as much damage as Experiment 607, even if he himself did not have natural time-manipulating powers.
Rufus, of course, could not be Experiment 607, as Ron was about 12 years old when he bought Rufus, while the experiments had only arrived to Earth about a year prior to the episode's events.
It is shown that Rufus will respond to both names: Rufus and Experiment 607.
This episode appears to take place sometime after the Kim Possible episode "Blush", as Kim mentioned in that episode the challenge she had talking to Josh Mankey.
It also appears to take place after "The Truth Hurts", as Ron mentioned in that episode that Drakken hadn't yet used an underwater lair (which he does in this episode).