In the blinding haze of the Black-Willow Swale, Nessa Vale moved with the calm, careful rigor of an engineer surveying a bridge pillar. While the air swirled with stinging ash and the distant thud of methane detonations rattled the ground, she unlimbered her ten-foot steel sounding rod, its surface graduated in inches with deep-filed notches.
Tomas walked beside her. His five-foot ash staff probed the turf two paces ahead. Meanwhile, Sile Rook held his great tall oak body-shield angled against the wind to deflect flying sparks and burning moss fragments.
Nessa drove the pointed steel rod deep into the trembling bog. She pressed the sound horn against the iron head of the staff. Her temple leaned close to the cold brass. She listened intently to the subsoil ringing tones.
“Solid turf for eighteen inches,” Nessa muttered through her vinegar mask, her voice muffled but distinct. “Then dry, stringy sphagnum down to four feet. At five feet... Hollow deep ring. The peat is already smoldering in that sector. There’s a two-foot void of glowing charcoal beneath our left flank.”
She withdrew the rod with a rhythmic wrenching motion, stepping eight paces to the north toward a low, gray gravel ridge that rose eighteen inches above the surrounding marsh. She drove the rod down again, throwing her weight onto the crossbar.
