Sister

The card was grey, no photo, a woman's silhouette for a face, and Lucía read it backwards at first, bottom to top, because her eyes went straight to the numbers.

“Inmaculada O. — Estimated relationship: Sister — Shared DNA: 2,612 cM (36.4%) — Shared segments: 54 — Longest segment: 171 cM — Sevilla, España”

The cold tea was dripping off the edge of the table onto the tiles. She didn't wipe it up. She read it again. Sister. Not “cousin”, not “close relative”, not “half-sister or aunt or grandmother”, the way she'd seen in the examples on the site. Sister.

She touched the card. A details page opened, with a chromosome diagram, twenty-two coloured bars side by side, and on each one blocks of colour wherever the two of them matched. They were everywhere. A line underneath, in small print: “of which approximately 24% fully identical”.