You stand on the south slope above the Cinder and do the test Penn loves because it is almost too simple.

Grand’s map (a copy of a copy, edges foxed) draws the river ruler-straight under the hill. Your feet draw a loop: oxbow, slow water, a parenthesis of mud and willows. Primary source: walking. Secondary source: the sheet. The map is not the territory. The territory has gone for a stroll.

“Rivers migrate,” Tansy says. “Penn’s word. They loop and leave. A road that believes last year’s paper is a road that lies down in somebody’s oxbow.”

You think of Penn’s town that kept the fen and stayed dry. Here the warning is already written: pave the sponge, and the next flood uses the square as a bowl. The myth encoded a care rule and gave it a catalog number so people would find it again.

The Atlas, if it is allowed, wants this loop. Brask’s blank does not.