I've seen this discussed on Fetlife a few times now, and it's a new term for me.
The best I can tell, in submissives it describes the place we go that's beyond subspace, when we're taken so deep it's all instinct and no human thoughts. When our bodies take over.
In Doms it describes the place they go when they let the sadist inside them take over. Some Doms say they can never let themselves go completely there because they think they'd go too far if they did. Others say they can let it take over, and that a safeword would pull them out of it.
I've been there, but I'd never had a name for it. I asked my husband about it and he understood the meaning right away, but said he doesn't let it take over. He reminded me of a few times we've played where he said he came close to letting it have control, and with that in mind he's right -- he doesn't need to ever let it completely take over. Seriously. Doesn't seem fair though -- that I get to indulge and he has to stay in control, but life's not always fair. I know the sadist in him must be fed, just as the masochist in me has to be, but feral space is about much more than that.
Is it possible to write a scene where feral space takes over? Probably, but I don't think I have. I have an excerpt up for Safeword: Davenport that might come close, but it's not it. There are other scenes in the story that are possibly closer -- this is the most intense book I've published so far, but I'm not sure it's possible to show how feral space feels. You lose words when you go there, you don't think with language, if that makes sense. So, how do you write about how it feels?
I'm trying to think of other fiction stories that might show it, and I think the "breasts through the door" scene in
As She's Told might show it from the submissive's POV, but only as she talks about it the next day. It's possible we see more of it during the summer at the rented house, as it's happening. Dark Angel Sounding shows a Dom who goes there, I think. And finally, I don't remember specific scenes, but in one of the middle books of Roxy Harte's Chronicle's of Surrender series it's possible the Dom and sub both end up there at the same time, but it's not gone into in detail -- the shark cage, the rock during the storm, they go to some pretty dark places together.
Is this a new term for you? Can you think of any fiction books that do a good job of showing it?