The field furnace took fifty minutes to build out of trench stone and a salvaged flue plate. Vell laid the fire bed himself while Yenna cut a windbreak into the slope above them with her uncut hand.
The flue plate had come off a collapsed smelter three ridges back, carried eight days against exactly this chance. Yenna had argued against the weight twice, then carried it herself for two of those days.
Stone went down in courses because a field furnace fails at its joints long before it fails at its heat. Vell had built four of them badly before Rynn showed him why the third course decides everything above it.
Wren sat at the furnace mouth through the build, watching the stone rise without offering her flank again. The offer had been made once already, so repeating it would have turned a decision back into a question.
"She wants the terms," Yenna said, driving the last windbreak stake, "not another round of reassurance about a number she has already read."
