Nera Coldfen knelt at the edge of the black water and pressed her leather chart against the surface. The ink markings drank the wet and darkened where the poison still lived. She was hunting the warlock who had ruined her flats, and the chart was her last clock. Each hour, the stains grew fainter. Each hour, her trail thinned. She worked outward from the dead tree at the center of the kill zone. Its ashen bark rose from the stagnant pool like a hand pulled from a grave. Around its blackened roots, the water had been strongest with the warlock's craft. Now the chart barely stained at all. A pale-finned serpent slid up beside her knee. Its frost-tipped fangs were bared, but it did not strike. They had a bargain, old and quiet. She showed it the fading marks on the leather. The serpent tasted the water and turned its narrow head north, toward the slow channels she had not yet tested. Nera followed. She pressed the chart again at every bend. Faint. Fainter. Then, at a sunken root, the leather drank deep and went almost black. The poison was thicker here. Something upstream was still bleeding it into the flats. She ran the channel back to its source and found a crooked little cottage squatting in the reeds. Smoke curled from its chimney. A clay jar sat cracked on the mud porch, leaking a slow dark thread into the water. Someone had been refilling the poison for days. Nera marked the spot on her chart and backed away without a sound. She returned to her timber lodge before dusk, spread the chart across the table, and weighed its corners with stones. The trail was no longer cold. But whoever lived in that cottage would know, by morning, that the jar had been seen.

Nera left the lodge before the stars faded. She carried a small tarnished mirror in her coat and a folded silver wire for the serpent's bargain. She did not know the warlock's face. She did not know the warlock's name. If she knocked at dawn and met the wrong eyes, the trail would close for good. She came at the cottage from downwind through the reeds. A pale fence of lashed bones marked the last safe line. Past it, the mud lay open and bare. She crouched behind a vine-choked stone well a stone's throw from the crooked porch and waited. The serpent slid up the well's wet stones and coiled by her boot. She set the mirror on the lip of the well and tilted it until the cottage door slid into the glass. Then she waited for the lamp inside to lift. The door cracked open. A young man stepped onto the porch in a stained apron, sleeves wet to the elbow. He knelt by the cracked jar and tested the leak with one finger. His mouth moved in a small, careful chant. Nera watched his face in the tarnished glass and marked every line of it. A burn scar ran from his jaw to his ear. His left hand was missing the smallest finger. She did not move. She did not breathe loud. She let him finish his work and go back inside. Then she eased the mirror into her coat and backed through the reeds the way she had come. She had his face now. She had his hands. She had not been seen. By the time the sun cleared the flats, Nera was already drawing him on the back of her chart — scar, missing finger, the angle of his chant. The warlock had a face at last. The next dawn would not be a guess.