As far as we've been able to reconstruct, it started Monday morning. Context: we love our great room, but it does have a bug or two, and one of the most noticeable is the screens in the windows, which are held in by nothing but pressure and prayer. We'd left one of the windows open a *bit* Sunday night, by accident, not even thinking about it.
Far as we can tell, sometime Monday morning, the kids were probably chasing around the house at a hundred miles an hour as usual, with Jedi probably harassing Jezebel. (Which he's been doing too often lately: really, he's been a bit of a bully.) He probably chased her into the great room, she jumped up onto the windowsill, he kept hassling her, she pressed into the gap under the window to get away from him, pressed against the screen -- which gave way at the bottom, and she fell from the second story. (From there, I can only guess about her adventures during the day.)
We didn't even notice anything was wrong until about noon, when msmemory pointed out that Jez hadn't been seen in hours; we grew more worried when Jez didn't show up at feeding time. By 4pm, she had torn the entire house apart and looked around outside, and was getting very unhappy. So I cut out of work promptly as soon as I was done with meetings at 5, came home and joined the search.
msmemory showed me the screen (still in its frame, but loose at the bottom), and shared her theory that Jez had fallen out the window. So I went outside -- where of course, the landscapers had shown up in massive force at 5pm sharp, six guys with Big Loud Machines doing spring cleanup, cutting and shredding and blowing and generally being as inhospitable to a cat as I could possibly imagine.
I put myself in her paws. If I was a cat, who had never been loose outside, had just fallen two stories, and was now surrounded by Evil Noisemakers, what would I do? So I began looking for every small, dark place I could find. And blessedly, I eventually found her -- not just in my tool shed, but crammed way in the back of the bottom shelf, the darkest possible space. She *was* actually mewing piteously -- but she's been incredibly quiet since she was a kitten, and her mews were almost inaudible. So I pulled her out (she was scared, but still had the clue that anything Daddy was doing had to be better than this), and brought her inside.
That wasn't the end of it, though. For the next two days, she's been treating her brother as Evil Incarnate. (Which is why I suspect he bullied her out the window.) She apparently decided that she has been pushed too far, too long, and wasn't going to put up with it. Which sounds fine in principle, but in practice has meant that every time he's tried to come near our bed (or anywhere else in her eyesight), she has gone into full growl-and-hiss mode. That, in turn, has freaked him out pretty badly, since from his POV all he's been doing has been playing, so they keep fighting. (This is particularly unfortunate when it's on the bed at 4am.)
There's not much way to sit cats down and explain to them that they need to chill out, so I've simply focused on reassuring both of them that they are still loved, and the frequent skritches seem to be helping. I can't say they're completely playing nice, but the chasing seems to be losing some of its life-and-death intensity, and is slowly getting back towards more normal play. I'm hopeful that, given another few days, she'll get over the trauma of her Adventure in the Big World, and things will settle down to something approximating normal...