Luke was eighteen when 5-year-old Hannah became so sick that the doctors said she needed a liver transplant. Their father had left us, and I couldn't reach him. I had already been tested, but the doctors ruled me out as a donor. Luke was a perfect match. "Sweetheart, I know you want to help her. But you're my baby, too. How am I supposed to watch them wheel you both away?" I begged him. "She's my little sister, Mom. How could I live with myself knowing I hadn't done everything I could to save her?" The doctors explained the risks and said they expected both children to recover. The surgery went well.
Hannah was getting stronger, but Luke was growing weaker by the day. Then one day, a doctor asked me to sit down. "We very rarely see complications like these," he said. "Right now, we're doing everything we can to stabilize him." They couldn't save Luke. It was a one-in-a-million case. I forced myself to keep going for Hannah. But I wouldn't wish the pain of outliving your child on any mother. Especially your firstborn.
I never had another child. I raised Hannah alone, keeping Luke's pictures where she could see them and telling her stories about her hero brother. Years passed. Hannah never had any serious health problems again. On her eighteenth birthday, I watched her laughing with two friends, wishing Luke could see his little sister all grown up. Then she opened an envelope tucked among the gifts. "Mom, did you make this?" The card had a photo I had taken of her three days earlier. Inside, it read: "Happy birthday, little sister. I promised I'd be here."
My heart stopped. Hannah had no siblings other than Luke. There was no one else who could have written that. "Is this somebody's idea of a joke?" Her voice broke. "Luke was my only brother. You all know how much I miss him." Before I could calm Hannah down, the doorbell rang. I asked her friends to stay with her, assuming more guests had arrived. But when I opened the door and saw who was standing on my porch, I grabbed the doorframe. "Oh my God! How… how is this possible? After all these years… you're here?"
Standing there with tears streaming down his face was Hannah's organ recipient—the transplant coordinator who had been following up on Hannah's case all these years, finally ready to meet the family. He explained that Luke had also put Hannah on his donor registry as a backup, and when the coordinator realized the date, he couldn't miss the chance to finally tell them both how Luke's sacrifice had inspired him to dedicate his life to saving others. He handed Hannah a sealed letter that Luke had written the night before his surgery, instructing the hospital to deliver it on her eighteenth birthday. Inside was Luke's handwriting: "Happy birthday, little sister. I promised I'd be here."