The envelope shouldn't have come to my house. I stare at it now, my hands trembling as I sit in my car outside St. Catherine's Medical Center. It's addressed to my daughter, Emma—a routine follow-up notice for her five-year transplant anniversary screening. Except the patient ID number is wrong. And the referring physician is someone I've never heard of. Dr. Helena Voss, Pediatric Oncology. Emma's doctor was Dr. Richardson. Hematology. I've read this letter seventeen times in the past hour, and each time, the words make less sense. Or maybe they make too much sense, and my brain is protecting me from understanding. "We're pleased to inform you that your bone marrow donation recipient continues to thrive. Per your request for anonymity, we cannot disclose the recipient's identity, but we wanted to express our gratitude for your selfless act five years ago..." Donation recipient. Emma wasn't the recipient. Emma was the donor. My phone buzzes. It's my brother, David. He's called three times since this morning. I haven't answered. I can't. Not until I know. Five years ago, Emma was dying. Acute myeloid leukemia with a rare blood disorder complication. She was thirteen, and the doctors gave her three months without a bone marrow transplant. I was a match, but not a perfect one—only 60% compatibility. We needed better odds. Then David showed up. My twin brother. The man I hadn't spoken to in seven years after our falling out over our parents' estate. He appeared at the hospital like some kind of guardian angel, dressed in his expensive suit, looking every bit the successful venture capitalist he'd become. "I'm a perfect match," he'd said, holding the test results. "And I'll pay for everything. All her treatments, all her care. Consider it my apology for how things ended between us." I'd cried. God, I'd actually cried and hugged him. Emma had the transplant three weeks later. David covered the $400,000 in medical expenses without blinking. She recovered beautifully. We rebuilt our relationship. He became Uncle David again, showing up for birthdays, holidays, her high school graduation last month. He saved her life. Except this letter says she saved someone else's. I push through the hospital's revolving doors, my heart hammering against my ribs. The administrative office is on the third floor. I take the stairs because I can't stand still in an elevator right now. "I need to speak with Dr. Helena Voss," I tell the receptionist, my voice barely steady. "Do you have an appointment?" "It's about my daughter, Emma Chen. It's urgent." The receptionist's expression shifts when she types the name into her computer. "Mr. Chen, I'll page Dr. Voss immediately. Please have a seat." I don't sit. I pace. I check my phone. Another call from David. A text this time. "Marcus, we need to talk. Where are you?" How does he know? How could he possibly know I received this letter? Unless he's been waiting for this moment. Dr. Voss appears fifteen minutes later. She's younger than I expected, maybe forty, with kind eyes that immediately look concerned. "Mr. Chen? I'm confused about why you're here. The letter that went out this morning was supposed to go to our bone marrow donor registry, not to—" She stops. "Oh God. You received Emma's copy, didn't you? The system must have auto-generated both files." "Tell me what happened five years ago," I say. "Tell me everything about my daughter's transplant." Dr. Voss's face goes pale. "I think we should speak in my office." ---