In this first half of the two-part series finale, Pleakley receives a strange alien device with various functions called a "Tetra-Tab". Ai and Stitch use the device to give themselves "brothers" named "Yong" and "Scratch". They all get along until Scratch starts convincing Stitch to destroy things, getting him to destroy a model city and then a construction site, with Ai, Jumba, and Pleakley finding out about the latter on the local news. After Stitch destroys the construction site, Scratch leads him to a city under construction and convinces him to start destroying it, finally getting Stitch to activate his metamorphosis program and grow into a giant monstrosity. Ai and Yong arrive on Jumba's hovercraft to see the giant Stitch beginning to approach the city.