The science of human origins is at the end of it, enriched in specific and permanent ways by what the child’s genome contained.

Between the beginning and the end, there is nothing but time — twenty-four thousand years of it, cold and dark and patient, waiting for the moment when the stone would be moved.

The moment came.

And what was under the stone was more than any single grave can usually hold: a child, a culture, a genome, and a key to the ancestry of a hemisphere.

Twenty-four thousand years is a very long time to wait.

The wait was worth it.