When she reached the bridge Lyra stopped. The river was a black mirror and the city flickered across it in broken stanzas. In the jacket’s breast pocket she slid out the plates and looked at them again. Patterns suggested things — orbit, recurrence, places in the sky where the air felt different, humming like a remembered song. She traced a finger along a curve and felt, absurdly, a kinship with the people who had once mapped stars on wet animal skins by torchlight. They, too, had tried to hold the sky’s shape and call it law.