A mist hung over the fjord, and above the mist - low - the iron moon. It was not from the night sky, but from the south, like a coin without a beat. Smoke rose from the long house of Torgeir, the ship's carpenter, and smelled of tar. Eir, his daughter, stood on the slip between the ribs of the new boat, listening to the wet wood talk. It wasn't the first time she'd heard it: a quiet whisper in the rhythm of the waves, seemingly advice, seemingly a riddle. That morning the sea gave the fishermen's nets a circle of black iron, heavy despite its size. It was smooth, without ornamentation, like a piece of the night itself. When Eir touched it, her fingers baked with chill, but the metal trembled as if blood flowed within it. A girl's face peeked over the edge, along with a few runes that no one had carved. The mark resembled lagos, water, but it was punctuated by a line of light. Eir tucked the circle into a bag under her woollen coat. The village circulated about the signs, as seagulls screamed over the bay and dogs howled for the day. Brynhild, the soothsayer, read the ashes from the fire, but the fire gave her an image she did not name. Torgeir spoke of the expedition as the ice was cracking and the riveting on the bow needed to be fixed. "You will go to trade, not plunder," Eir reminded him, as she always did. "We will go to listen to the wind," he replied with a smile, "and it knows what to bring." Dusk fell fast, a green dance descended from the sky, and the iron circle trembled harder. From the buoy by the rock came the thump of a horn, long as a dragon's breath, though no one held the horn. Leif, Eir's cousin, pointed to the mouth of the strait, where the water, usually restless, flattened suddenly. "Can you hear it?" he asked. "As if someone is singing from the bottom." Eir nodded wordlessly, feeling the hair on the back of her neck rise. A circle pulsed in the bag, as if responding to a song. Embers were burning in the long house, but the girl did not sit down at the digestion. Brynhild grabbed her wrist and squeezed it until her knuckles turned white. "You are not the summoner," she whispered. "And yet it came to you." Eir pulled her hand away gently, as if she were pushing back a reed stalk. "I don't want it," she said truthfully, "but I hear it." Torgeir returned from the wharf, carrying a whale's rib on which old hands had carved a map of the stars. A corner was missing, as if someone had broken it off long ago. The shape of the missing piece matched the circle. The shore became quiet to the point of unnaturalness, as if the fjord had held its breath. Eir and Leif ducked into the boat shed and slid the small boat down the wet beams. "We'll just have a look," Leif muttered. "If it's stupid, we'll turn back." They sailed towards a dark cleft between the cliffs where a milky mist was gathering. A circle broke out of the bag, hit the bow and clung to it, lighting up with a thin strip of light. The water beneath the boat rippled, as if something huge had turned just below them, and from the cleft emerged....