Kat and Doofenshmirtz were walking one day when Kat sat, and wouldn't get back up. Was she just being a stubborn brat, or was something wrong? Then, he noticed how pale her fur was. Was his best pal getting old? Kat had very bad arthritis in her hips. They often collapsed on her. She was deaf, and was almost blind. One day, she collapsed on her old, shot, creaky, hips, and wouldn't get back up. Luckily, the vet saw. After a few long moments, the vet came out and said they would have to go into serious surgery. Doofenshmirtz went back with the vet, who was about to give her a shot. "There's a small chance she won't survive this. Are you sure you're ready?" He nodded. The vet slowly gave her a shot. Kat's eyes closed. "She's gone." the vet said. She was old, it was her time. One day, though, he found a stray, light blue alien. He looked like he had just seen a ghost- and he couldn't be more thrilled about it! Kat had returned- as a boy! "Zapnis!" Doofenshmirtz said. The alien looked at him as if to say, "Have we met?"