Behind the washer and dryer, or other furniture in the house? Under the steps down from the kitchen (I forget if you have them,actually, but that's a spot my cats hide)?

ita, your mom is a total badass. I just hope she's OK with me saying that, because ...well... she's a badass.

And oh, my lack of sleep is hitting me now. I did get a bunch of grading done, and 4 loads of laundry and 3 loads of dishes, so not too bad. I want to nap now, but I need to clean up the front rooms a bit and start up a red sauce. We're having friends over for dinner.

Oh yeah, hiding place for Zed: under some odd piece of furniture, like a couch or a dresser? Our cat Folly loves hiding under furniture, and I notice that I often forget the non-bed items. Washer/dryer is another good guess. Poor Zed!

Washer dryer are in the garage, where he shouldn't have been able to get, though I have looked through it.

I've checked under all of the furniture and checked all of the cabinets, more than once.

Assuming I can find him, Cat's name is now Houdini.

Or inside the furniture? I've had cats wriggle up through a hole in the bottom lining of a couch or a bed's box spring.

Yep.

If there's a toy or some food he really likes, I'd sit in roughly the middle of the house with it and let it get quiet -- i.e. leave all the doors and cabinets open, but stop walking around or calling him. Just chill, and in the quiet maybe he'll get curious and come out to see what's up.

If you don't think he got into the garage and he doesn't seem to be in the kitchen or dining room, maybe it wasn't him you heard - I hear neighbor's cats meowing piteously outside m y house way more than I hear my own. The most likely place for him to hide would be back in the room he's used to, I'd think.

Cat (and I was lying about the Houdini) just strolled by me on the way to his room, which YAY, but also damnit, because now I don't know where his hiding place was.

That little bastard. I hope Dita isn't taking notes.