Using ListMyKitty's inspiration about litterboxes and scents, I scooped out the litterboxes and put the um, clumps of stuff all around my property. At night, I slept with the windows and front door open (due to a security screen door). A few days later, at 4 AM, I heard a cat meow outside. I got up and went outside, and it was Shamgar! Hungry, thirsty, and in need of lots of pets, pats and attention. Thank you for the advice. It was priceless. Thank you to all the total strangers in my neighborhood, the local shelters and pet store who said they'd be on the lookout and who let me post my flyers. Neverending blessings to you all!