Their vastnesses concealed since an era predating the earliest mammals, two titanic chasms are uncovered beneath the canopy of modern Siberia. Lining the granite walls of the first, high above an orderly reservoir of fossilized eggs, an inscription spanning eighty-five miles describes the genome of a proto-mammalian species eradicated during the Permian Extinction. In the next, researchers discover etchings of the constellations as they would have appeared across the eons; a global timeline of ten billion years remembered and foretold by a primordial intelligence beyond our own. Armed with a genetic recipe, compelled to act by the harrowing implications of a pattern detected in the timeline, an international effort begins to return that species from extinction before mankind encounters its own. The human race has only just learned to pluck at the strings of life on Earth. Will the curtains rise on a siren's song?Where will they fall?