My grandmother kept a jar of buttons she would never explain. After she died, I finally emptied it onto the table. There were dozens. Every one had a date written on the back. Most were decades old. One was dated next Tuesday. I laughed. Then I stopped. Next Tuesday was tomorrow. The button was red. I showed it to my brother. “Throw it away.” I did. The next morning, it was back in the jar. We decided to ignore it. At nine that evening, someone knocked on the front door. It was a woman I'd never seen. She was wearing a coat missing one red button. “I knew she'd leave it to you,” she said. “Who?” “Your grandmother.” The woman walked inside as though she'd lived there. She explained that my grandmother had spent fifty years preventing certain events from happening. The buttons were markers. Each represented a disaster she had somehow interrupted. A fire. A train crash. A drowning. A war. “And tomorrow?” I asked. The woman looked at the red button. “Tomorrow is the last one.” “What happens?” “Nothing, if you do exactly what your grandmother did.” She handed me an envelope. Inside was a bus ticket. I followed its instructions to the station and sat on a bench until midnight. At 11:58, a man ran towards the tracks. I stood. I shouted. He stopped. A train screamed past. The next morning, I returned home. The red button was gone. I finally understood why my grandmother had never explained the jar. Some people spend their lives being heroes. Others spend theirs making sure nobody ever knows they were there. The marathon ended, as these things do, with a quiet cup of tea.