But there is one place where even identical twins are not identical, one thing nature does not copy between them.” She let the pause sit.

“Fingerprints.

Twins share almost everything, but not their fingerprints.

Those are formed by chance, in the womb, and no two people on earth have the same, not even two people who share a face.”

“We were able to pull archived fingerprint records,” she went on, “from before the crash.

Prints on file for both brothers, taken years ago, for ordinary reasons, and kept.

And then we compared them, quietly, to the man who has been living these three years as Sebastian Morales.” My throat had locked; I could not have spoken if I tried.