Alex Ryan knelt at the edge of the yew grove and watched the dark water crawl toward the roots. It moved slow, but it moved. A thin oil-shine rode the top of it. Danu had named the taint an hour ago and gone quiet since. Alex had nothing in his coat but rosin and a folded chord chart. He set his bass against the nearest trunk. The yew was older than any church he had played in. Its lowest root drank from the ground six inches from the creeping stain. He knew what would work. Hozier would work. Hozier had already pulled black rot into his chest once and had not slept right since. Alex would not ask him. He had built his life around not asking him. He was here to keep the grove alive so the bass in his hands would not be the last piece of it left standing. That was the promise. Ask Hozier, and the promise broke. He whistled two low notes through his teeth. The ravens came down out of the yews without sound. They landed on his shoulders and on the roots and on the stones and waited. He did not like being watched by them. He spoke anyway. "Go and get Her sister," he said. "The one who patrols. Tell her the border's wet." They lifted off in one piece and were gone. Danu stepped out from behind the largest yew. Small, barefoot, crown of stones and yellow flowers. She looked at the water, then at him. "Thank you," she said. "For calling my little sister. I would not have." "You needed her." "I needed her a long time." A crow dropped through the branches and hit the moss as a woman. Dark hair, red cloak, mud already on her boots. Morrígan did not greet her sister. She crouched at the edge of the seep, dipped one finger in, and tasted it. "Fomorian," she said. "Old blood. They can smell the horse we drained." She wiped her mouth on her wrist. "Winter's calling in favors." Danu said, "Can you hold the line here?" "I can hold anything that has an edge." Morrígan looked at Alex. "You. Play something with a floor in it. The roots need something to stand on while I work." Alex sat down between two yews. He set the bass across his knee and pulled the low string. The note went into the ground before it went into the air. He felt the nearest root tighten around it. Morrígan walked into the black water without flinching and began to speak names to it in a language Alex did not know. The water stopped moving toward the trees. It did not retreat. It stopped. Danu watched the tree line past the grove. Something out there had noticed. She said, quiet, "They are coming now. All of them. Because you called her." Alex kept the note steady. The roots drank clean ground for one more hour.

Morrígan stepped out of the black water and shook her cloak. The water stayed where she had stopped it. She looked at Alex where he sat with the bass across his knee. "Keep him out of this," she said. "The bogman. He's already carrying rot in his ribs." Alex nodded. She crouched close so only he could hear. "Say it back to me." "He never knows I called you." "Good." She straightened. "I'm going to find the witch's machine. I want to ask her about noise." Then she was crows again, a black handful of them, gone over the trees. Alex walked back down the path toward the cottage. He could hear music before he saw it. Two instruments, easy and slow, folded into each other. He came around the hedge and stopped. Hozier sat under the woven arbor with a fiddle on his shoulder. Florence had a small banjo across her lap. Moss ran up the bench legs and touched their boots. The notes settled in the air like weight on a scale. Alex sat on the far end of the bench. He did not lift the bass. He wanted to hear them without adding to it. Hozier looked at him once, mild, and kept playing. The song had no hurry in it. A shadow crossed the grass. Just cloud, or a bird. Hozier lowered the bow. "Something's watching the fence line," he said. Florence's hand stilled on the strings. "The old blood?" "Or worse." Hozier set the fiddle on his knee. He looked at Alex. "Danu named a name this morning. Fomorian." Alex kept his face flat. Hozier said, "I've been thinking about my pact. The one that pulled me up out of the peat." He touched his own chest. "I think I made it partly so I'd be here for this. So there'd be hands for it." Alex felt the promise crack under his ribs. Hozier had guessed his own use before Alex could hide it from him. He opened his mouth. He closed it. Florence started a new chord, uncertain, and it did not match what Hozier had been playing. Hozier tried to follow her and lost the line. The song came apart between them. The moss at their feet flinched. The air went cold. At the edge of the yard, between two hazels, an elk stepped out of nothing. Its antlers were wider than the arbor. It did not lower its head. It looked at Hozier the way weather looks at a house. Florence set the banjo down without sound. Hozier stood. Alex found his voice. "I called her sister," he said. "This morning. Without telling you." Hozier looked at him. Not angry. Just seeing him plain. "I know," Hozier said. "Play the floor note. It's asking for one." Alex pulled the low string. The elk stepped closer to the grove, and the secret between them was over.

Alex held the low string and let it ring. The elk stood at the edge of the yard, watching Hozier the way weather watches a house. The note traveled out from the bass and lay flat across the grass. It reached the elk's chest and stopped there. Alex felt it stop. His string could carry the sound to the trunks of the yew grove, but not down. The taint was under the ground now. The roots needed a note that could drink from below, and his bass alone could not send one that deep. He played the note again anyway. The moss at Hozier's boots lifted a little. Florence held her banjo against her knee and did not touch the strings. Hozier said, "It's not enough." "I know," Alex said. "The roots are drying from underneath." Hozier looked at the elk. The elk did not move. A sound cut across the yard. Not a bird. A single piano chord, heavy, rolled in from the path. A woman came around the hedge pushing a cart of brass pipes and rune-cut wood. Florence sat up. "Isa." Isa Machine did not look at Florence yet. She looked at Alex's bass, then at the elk, then at the ground between them. She set the brake on the cart. "You're short a register," she said. "I heard it from the road." She was Florence's anchor, the one who kept Florence's magic from flying apart. Alex had never played with her. He did not know if she would follow him or run him off the note. Isa opened a panel on the cart and set her hands on the low keys. "Give me your floor," she said. "I'll take it lower." Alex pulled the string. Isa caught the pitch and dropped it an octave through the pipes. The cart hummed. The sound went into the ground, not across it. Alex felt his hands warm on the yew. He held the note steady. The elk lifted its throat. The elk sang. One note, so low it moved inside their ribs. Florence pressed her hand to her chest. Hozier closed his eyes. The note ran down through the soil and found the roots. Alex felt it reach. It was the sound that had first pushed order into chaos. Awe held him still. The black under the grove pulled back. The moss went green again at the edges. The elk stopped singing. It looked at Alex once and stepped back into nothing between the two hazels. Isa lifted her hands from the keys. "That wasn't me," she said. "That was the animal." "I know," Alex said. His hands were shaking. The grove was drinking. He could feel it through the bench. Then Florence stood. She was looking past the arbor, toward the path Isa had come down. "Isa," she said. "Who did you leave with the cart?" Isa turned. Her face went flat. "No one," she said. "I came alone." Something on the path was already moving toward them.