The scientific findings that followed from that moment of light — the radiocarbon dates, the morphological analysis, the ancient DNA extraction, the haplogroup determination — are all extensions of the same basic act: someone went deep enough to look, and brought light to something that had been in the dark for a very long time.

What they found told a story that the darkness had kept secret.

A young woman, fifteen or sixteen years old, who had lived in the Yucatán at the end of the Ice Age, who had walked in the light of a different world, who had died in the dark of the same cave system that is still there beneath the same peninsula.

Who had carried in her cells a mitochondrial haplogroup that connected her unambiguously to the founding population of the Americas.