Yep, I agree w/Jen on this one; tough love. All of my cats were outdoor cats when I got them, some even feral. They've never been outdoors since the day I brought them in and, believe me, some have tried to dart out the door. Now, though, they're content to be indoors but it took a while. If, however, you feel that your neighbor would adopt Potter and keep him in and you'd feel better all the way around, go for it.