I FOUND HIM!
Tail and all! He's back in his cage, adventure over. Thank god.
I had searched and then sealed off the wall that is all a book case and removed many boxes and hiding spots. Then, giving up for the night and planning tomorrows hunt, I debated about a short trip to grab a glass of water, or to just go to bed. Deciding on the water, I got up and went to the door. Decided, randomly, to hit a light to do a visual scan of his cage and room. (I'd left his cage open with food in it to try and lure him back). Seeing nothing I turned around and went to open the door and step out... when I look down and nearly hit him! Half on the door, half on the carpet, in the corner of the frame he's sitting there, caught in the light.
*gingerly snatch*
Back into his cage. SECURE THE DOOR. Stare at him.
I can't believe it.
So close to his cage and to my female too. And the couch. And Piano. (Things I really don't want to imagine him hiding in.)
I can't believe it.
Phew.
Tomorrow I design velcro door locks. I've never made that mistake before, and I pray I never do again!