Kitty's hurt
I don't know what happened. We couldn't find him earlier today, and when we got home (about 10:45pm) tonight, someone found his flea collar on the porch.
I decided to check out back one more time before bed to see if he was back home and ready to come in, and I heard him out there crying, so I went out to find him. He was hiding between a tote and the crate in which we keep the swimming pool. I picked him up and he cried, and I set him on the porch and saw that he was having trouble walking, and was obviously in pain.
My first thought was that he'd been hit by a car (had a cat, Benny, who had gone through that when I was 15/16) so I brought him in and laid him in the utility room (where the litter box is) and went to get Robby.
We brought in a flashlight (utility room light is burned out at the moment) and looked him over - his behind is torn open, not sure how. Either he was hit and scraped along the ground... or someone caught him and did something to him... or an animal attacked him... hard to say. Robby said we'd look again in the morning to see if we can figure out better what happened.
Poor kitty!