Baldr stood in the courtyard while an axe bounced off his chest. He did not flinch. Nothing in the nine realms could cut him. His mother Frigg had made every plant, animal, and element swear an oath to spare her golden son. Light spilled from his skin as the gods laughed and reached for more things to throw. Baldr laughed too, but only with his mouth. Lately a cold thought had settled in him. An oath from everything meant someone, somewhere, had proof of what could break it. He wanted to find that one weakness himself, before an enemy did. Thor tested the oath with fists first, then with lightning. He hurled a bolt straight at Baldr's face. It sparked and died against his cheek. "Still nothing," Thor said. He shrugged and threw a spear. It snapped in half. "Throw softer," Baldr said. "I am trying to listen." "Listen for what?" Thor asked. He did not wait for an answer. He rarely did. Baldr could not explain it. When things struck him, he sometimes felt the smallest tug, like a needle before it broke. He wanted quiet to find that feeling again. But the gods only grew louder. A stone here. A knife there. Every hit drowned the tiny signal he chased. Then Loki arrived. Baldr felt the mood change before he saw him. The laughter turned sharp. Loki was Odin's blood-brother and the cleverest of them all, but his games always cut closer than the rest. He grinned at Baldr the way he had grinned since they were boys. "You look bored, nephew," Loki said. "Let us play the old game." His body folded and stretched. Fur poured over his skin. A gray wolf stood where Loki had been. It bared its teeth and lunged. Baldr ran, the way he had run as a child, laughing and afraid at once. The wolf chased him past the golden hall and into the trees. Baldr crashed through the brush. Branches slapped him and broke. Nothing marked his skin. The wolf snapped at his heels, close enough that Baldr felt its breath. He leapt over a fallen trunk hung with pale green vines. A thin leaf raked his forearm. He stopped. A line of red rose along his arm. Blood. Real blood, bright against his glowing skin. He touched it and stared. In all his life nothing had ever pierced him. He looked at the vine, its small waxy leaves and white berries, and did not know its name. The wolf skidded to a halt beside him. It sniffed the air, then Baldr's arm. Loki's shape returned, kneeling in the leaves. He was looking at the scratch, and Baldr could not read his face. "You are bleeding," Loki said quietly. "I know," Baldr said. He closed his hand over the wound. "Tell no one." But Loki's eyes had already moved from the cut to the vine.