Since my vet said that Sky is healthy, I decided to try to introduce him to the gang this evening. Sunny seemed very scared and then ran off. He also did this with Cirrus and now their best friends. Storm hissed and growled a few times but seemed to relax soon afterwards. Cirrus sniffed and just sat and watched Sky and then decided to run away. I think it went better than I thought it would. Now Sky is sleeping on my bed and the other 3 are out in the living room. Sky is so easy going that I know it won't take very long for the others to love him as much as I do. Thanks again for all of the nice comments. I really appreciate it.