Marcus kept his eyes on the floor. “Twelve years ago, I signed a contract with my cousin’s company,” he whispered. “A fertility study. I was paid to donate, and I never told you. Last year, the clinic called. A child was born from it. A girl with a rare heart condition, and she needs a sibling donor.” My mother stopped calling my name. The porch went silent.

Helen pulled a folded letter from her purse with trembling hands. “The little girl’s name is Grace,” she said. “Her doctors say Harper may be the only match. We saw Harper and panicked, because she looks exactly like her.” I stared at the photograph clipped to the page, a six-year-old with my daughter’s dark curls, and felt the world tilt.