I can't find my small black cat

ETA: I found her. She was hiding in the office closet -- I forgot she can pry the door open on that one. She's definitely under the weather, though. I think she'll have to go to the vet.

Saturday, I got in close to midnight, and fed her. Not long after, she threw up a bunch of slightly used food, and I cleaned it up. She slept with me.

Sunday morning, she threw up a bunch of liquid. I praised her for doing it on the bare floor instead of the carpet, and cleaned it up.

Sunday evening, she didn't come when I put her food in the dish, which is unusual, but not unheard-of. Also, she hadn't finished all of the previous day's food. Also unusual but not unheard-of.

Sunday night, she didn't come to sleep with me, which sometimes happens, but not often.

This morning, I can't find her anywhere. I've called and called and looked in all the corners I can think of. I didn't go out all of yesterday, so she has to be in the house somewhere.

At this point, I'm terribly worried that I'm looking for a body rather than a sick and hiding cat. She's only four years old, and has never been sick other than the inevitable occasional hairball.

I'm working at home, and I keep wanting to take the flashlight and shine it in corners I've already checked.

Cat update

I took Morwen to the vet at 5 pm. Usually it's a challenge to get her into the cat carrier. This time it wasn't; I closed the door of the office (to remove the potential escape route), hauled her out of her hiding place in the closet, and she went into the carrier with minimal fuss. Which was sad and unnatural.

Dr. McMenomy looked at her and took her temp. Then he opened a can of yummy wet cat food and offered her a taste. She ignored it, even when her nose was more-or-less rubbed in it. He drew some blood for tests, then sent me back out with her to wait for the results. About 40 minutes later, he said that she was dehydrated (no surprise), but her other results were mostly normal. He gave her subcutaneous fluids for the dehydration, an injection of something that I don't recall to try to jumpstart her digestion, and a Kaopectate for cats prescription to be given three times a day. Total cost was $300 -- so far. I'm supposed to call Dr. Mac back tomorrow with an update.

She peed in the carrier coming home, which I suppose was the effect of the fluids. She's back in hiding in the closet. I pulled her out to give her the medicine, and I hope most of it went down -- it looked as if she drooled out at least some of it.

Her back end was all damp, but it wasn't all that stinky, so I'm not sure what's going on. But she's clearly unhappy, and can't explain to the stupid human just what the problem is. So I'm unhappy, too. Poor Morwen.