Milthy Myrtle pressed her thumb into the largest mushroom on her cloak, and it caved like wet ash. Rot. The same grey rot had spread to a dozen more caps overnight. Each ruined mushroom was a spell she could no longer cast. She had waited three hundred years to find an apprentice, and now her magic was dying before she had someone to give it to. She stood in the muck outside her sunken bog cottage, moss dripping from its roof. Her crow watched from the doorframe, balanced on its one leg. "Don't look at me like that," she told it. "I know I'm running out of time." The whiskers on her chin had gone from white to nothing much at all. When they greyed for good, her lore would die with her. Milthy needed to know where the rot came from. She knelt and pressed her palm to the black water. The last healthy mushroom on her hood glowed faint green. It pulled her, like a hound on a scent, deeper into the swamp. She followed for an hour. The reeds thinned. A patch of mire spidergrass barred her path, its red mouths snapping at her boots. She fed it a handful of grubs and stepped past while it chewed. Then she saw it. A totem rose from the mud, three stone faces stacked and snarling, horns curling from each skull. Dark runes bled down its surface. The air around it breathed rot. Every fern within twenty steps had turned to grey slime. This was the source. Someone had carved it and set it here on purpose. Milthy's guiding mushroom flared bright, then blackened and fell off her hood into the mud. She had found the sickness. She could not touch it. The corrupting magic was thick as tar, and she felt it reaching for the last spells left on her cloak. A voice came from behind the totem. "You shouldn't have come, old woman." A small figure stepped out. His skin was grey-green, his eyes lit like green coals, and red mushrooms grew from his skull the way hers grew from her cloak. He leaned on a bone-tipped staff. He wore the swamp's rot like a crown. "You did this," Milthy said. "You're the one poisoning my magic." "Maldrus Sporeweft," he said, and smiled with rotten teeth. "They banished me. So I brought the rot to them. To all of it." He tilted his head. "Your little spells are already mine." Milthy looked at her cloak. Half the caps had gone grey while they spoke. She had no counterspell strong enough, not here, not now. So she did the one thing a witch of three hundred years knew to do when she could not win. She backed away. "This isn't over," she said. She fled through the reeds, her crow flapping ahead. She knew the enemy now, and she knew her time was shorter than ever. She had to find an apprentice before the whole swamp rotted through.