In the permafrost, through thirty-one thousand years of history, the teeth held what they had always held: the complete molecular record of two children who were real and alive and human in every way that matters.

Science learned to read that record.

And what it read changed what we know about the story of ourselves.

Above the Arctic Circle, in the Ice Age dark, children grew.

Their teeth fell out.

The ice kept them.

And eventually, the ice and the science and the time all came together, and we learned: there was a lost population, here, in the deep cold, whose story reaches across thirty-one thousand years to the ancestry of millions of people on the other side of the world.

That is what the teeth said.