I adopted a 9 yr old kitty about 1 month ago. I'm still working on the introduction in stages; home base, feeding opposites sides of the door and site swapping. My adopted cat stays in my bedroom with toys, food, water, cat tree and litter box. She is always calm and relaxed there and has no reaction when my resident gets vocal, she's always been a talker. I wanted her to bond with me and my resident cat didn't usually sleep in my room so that hasn't been a problem. My resident cat is 11. The new kitty was in the shelter for a year but is sweet, loving and very social. Her owner gave her up due to being homeless. They have very similar personalities. Its been a slow process. Recently I have my resident cat in a large kennel and would bring in the new cat for short visits. That was going well, in fact my resident cat would go into the kennel cage on her own anticipating the visit, until tonight when suddenly they lunged at each other and tried to fight through the cage. I have no idea what happened other than the adopted cat got a bit closer than usual. Should I start the introductions over again from stage 1 or just try to proceed? I love both cats very much, rehoming either isn't an option. I can see this process may be months or longer. Please wish me luck I'm feeling a bit shaken and defeated.