Yesterday marked some kind of breakthrough for Caruso, I think.
I looked into our guest bedroom, where he's spent a lot of time hunkered under the bed, and there he was, curled up on one of the pillows, out in the open! We did a little bit of bonding, and I left him there, still on top of the bed. About an hour later, I saw Harley sitting in the doorway of our bedroom (an unusual place for her to be), so I peeked in and saw Caruso lying on our bed! (I'll know he's been accepted into the pack when all three cats end up sleeping with us at night.)
Unfortunately, Harley, who is a typical tortoise-shell cat, with enough attitude for several other kitties, got pissed that he was in her spot, and chased him off the bed and back into the guest bedroom. She began a fight, but I think David managed to make it clear to her, in his inimitable and quite successful way, that she was not allowed to harass Caruso. So far today, she's left him alone.
I went looking for him when I woke this morning, and couldn't find him anywhere. I checked all of his hidey-holes with no success, when suddenly I saw his head pop up from behind a small table that sits in the center of the bay window in our dining room - he'd been stretched out on the windowsill (something neither of our huge cats could possibly manage) and I didn't see him until he looked up. He let me come over and scratch his ears, and then he spent an hour or so lying in a pool of sunlight while David worked on the crossword puzzle nearby. When I returned from volunteering at Animal Aid, Caruso and Sam were lying a few feet apart on the dining room rug, enjoying the warmth of the sunlight that was streaming in the windows.
It looks like this is gonna work!