Sif stood at the golden doors of Vingólf and watched the man she meant to destroy walk in wearing gold. Loki cut off her hair once. He shaved her scalp bare while she slept and laughed about it. The dwarves gave her new hair, real gold that grew from her own head, but the shame never washed out. She had sworn to pay him back so fully he could never mock her again. Now here he was, home in Asgard, and she had no way to hurt him. That was the trouble. She knew Loki. Every threat she made, he would twist away from. Draw a blade, and he became a fly. Corner him, and he talked his way loose. She had spent months hunting for one weakness she could press. She had found none. He saw her and smiled. "Sif. Your hair looks well. Better than the last time I saw it." Her hand went to the long gold braid at her waist. "You should not have come back." "And yet." He spread his arms. His golden cape swept the floor. "Odin still calls me brother. What can you do to me here?" Nothing. That was the answer he wanted, and it was true. She could strike him and he would slip loose, and then he would tell the tale for years. The god's wife who lost her temper and her hair both. Sif made herself smile back. "You're right," she said. "I can do nothing." The words tasted like ash. But saying them changed his face. He relaxed. He thought he had won, and a man who thinks he has won stops guarding himself. "Sit," she said. "Drink. Tell me how you crossed the bridge past Heimdall." He liked that. He loved to be admired for his cleverness. He sat and poured himself a cup and began to boast. He told her about a black dust that blinded the watchman's eyes and ears. He told her how he walked across the rainbow bridge while Heimdall groped in the dark. He told her he had gone hunting for something precious. A weakness, he said. The one weakness of the one god no weapon could touch. Sif kept her face still. She had come for his weakness and he had just handed her someone else's. Loki had found the flaw in Baldr, the shining god, the son of the Queen. If she carried that to Frigg, the mother would tear Loki apart to protect her child. She stood and set down her cup. "You've helped me," she said. "More than you know." His smile faltered. Too late. She was already at the doors. She still had no way to wound Loki herself. But she no longer needed one. She had his secret, and she knew exactly whose ear it belonged in.

Sif crossed the wetland path to Frigg's palace with Loki's secret burning in her chest. He had boasted of a weakness in Baldr. But he never named the plant. He never showed it. Sif carried only his words, and words from Loki turned to smoke in the hand. If she named the wrong plant to the Queen, Frigg would call her a liar and throw her out. She found the Queen at her loom in Fensalir. Frigg did not turn. Her gold keys hung at her belt, and her blue cape pooled on the wet stone. "You come with a mother's fear on your face," she said. "Speak it." "Your son can be killed," Sif said. "Loki found the way. He crossed the bridge in secret and hunted for it." Frigg's hands stopped. She rose slowly. "Every plant swore to spare him. Every beast. Every stone. Name the thing you claim I missed." Sif's mouth went dry. She did not have the name. "I don't know it. He would not say. But I swear he holds it." The Queen's face hardened. "Then you bring me a rumor. My son is loved by all things. You want me to break Loki on a guess." She reached for the loom again. "Leave." Sif had failed. She turned toward the door, and the water outside went still. A woman stood in the doorway. Pale skin, black straight hair, wings of dark bone folded behind her. Loki's daughter. Sif had heard of her, the one who ruled the dead, the one who knew each name and each hour of death. Fear crossed even Frigg's face. "He is my father," Hel said. Her voice was flat and cold. "I know what he carries. He showed me before he showed anyone." She looked at Sif, then at the Queen. "You want the name of the plant. It grows in Baldr's orchard. It bore no oath because it was too small to notice. Mistletoe." Frigg went white. The word struck her like a blow. "Mistletoe," she whispered. "I passed it by. It was young. I thought it too weak to matter." Her hand found the edge of the loom. "I forgot one thing in all the nine realms, and Loki found it." Sif's guess was now the Queen's certainty. But she stared at Hel, and dread crept up her spine. Why would Loki's own daughter hand his secret to his enemies? Hel answered the unspoken question. "My father thinks he holds all the power now. I wanted him to learn he does not." She smiled without warmth. "And I wanted you to owe me." Frigg turned to Sif, tears bright in her eyes and fury behind them. "Go to Odin. Tell him the mistletoe. Tell him Loki has it." Sif had her proof at last. But she left Fensalir knowing she now owed a debt to something worse than Loki.