Project Mycelium has bodies doing wrong things on nearly every page. A man who's been dead for six hours and is still walking. Threads under skin that don't answer to a pulse. A graft that isn't quite a transplant. I made an early decision, before I'd written very far into it, that I would never sensationalize any of that — no gore for its own sake, no lingering on wound detail for shock value.
The actual technique is smaller than it sounds. State something ordinary and procedural. Let the wrongness sit underneath it, unstated. His pulse ran slow and perfectly even. A resting corpse breathes faster than that. Eight respirations a minute, when a body that's actually failing usually manages more, not fewer. None of that is gore. It's arithmetic. But it does work an adjective can't, because the reader has to do the math themselves, and a fact you calculate yourself lands harder than one you're handed.
I think of it as trusting the reader's own sense of wrong more than I trust my own vocabulary for horror. A pulse rate is scarier to me than any word I could put next to it.
That's most of the craft note. The rest of it is just doing that same move a few hundred more times and hoping it doesn't get tired.
— C. W. Lindmere