You do not shout. Shouting in Elderwood is like kicking a library.

You kneel. You put two fingers on the leaf-mould, the way Thorn taught you last summer, and you say the greeting that is really a question: May I pass as a neighbor, not a net?

A fern parts. Thorn of the hollow is already there, of course—leaf-stained, hair in a practical knot, eyes the color of wet bark. Young for an elf, which still means older than your mill in patience.

“You saw the white one,” Thorn says. Not a question. “If you chase a keystone like a prize, the wood comes apart.”

“Keystone,” you repeat.

Thorn points at an old oak, then at a hole in the soil where a grub has been working, then at the empty air where a wolf-story used to live. “A stone at the top of an arch. Pull it, and the doorway forgets how to be a doorway. Some beasts are like that. Some trees. Even a fungus-thread you cannot see. The Pale One walks the last uncut seam. Take the horn-that-isn’t, and you take the seam.”

Mira, at the edge of hearing, holds still like a good secret.

Thorn’s rules are simple: no running at living things, no breaking roots for fun, no taking what the wood still needs.