I’ve worked the night shift at a private bank in London since 2004. In twenty-two years, I’ve cleaned offices belonging to millionaires, politicians, and executives who couldn’t even remember the names of the people who emptied their bins. But one mystery followed me for almost a decade. Every Monday morning, I found a £50 note underneath the CEO’s desk. The CEO, Mr. Richard Collins, was one of the wealthiest men in the building. He drove a black Bentley, wore handmade Italian suits, and rarely spoke to anyone below management level. At first, I thought the money had fallen out of his pocket. I handed it to reception. The following Monday, another £50 appeared. Then another. After six months, I began leaving the notes exactly where I found them. One night, I stayed behind to investigate. At 1:40 a.m., I heard the lift doors open. An elderly woman stepped out carrying a plastic shopping bag. She wore an old brown coat and walked slowly toward the CEO’s office. I watched from behind a filing cabinet as she entered the room, placed a £50 note beneath the desk, and sat in the CEO’s chair. Then she began to cry. “I did what you asked, Richard,” she whispered. “I brought it again.” I stepped into the doorway. “Madam, this floor is restricted.” She looked at me without surprise. “You must be the new cleaner.” “I’ve worked here for sixteen years.” She nodded sadly. “Then you’ve been here long enough to know that Richard doesn’t work here anymore.” I frowned. “Mr. Collins is in his office every morning.” The woman slowly shook her head. “Richard Collins died in 2015.” I laughed nervously. “That’s impossible. I spoke to him yesterday.” She reached into her shopping bag and pulled out a newspaper clipping. The headline read: BANKING EXECUTIVE FOUND DEAD IN PRIVATE OFFICE. The photograph showed Richard Collins. The date was October 12, 2015. I stared at the woman. “Who are you?” “My name is Margaret Collins. I was his mother.” She explained that Richard had died suddenly at the age of forty-two. The bank had kept his death quiet while the board settled his affairs. According to the official report, he had suffered a heart attack. But Margaret didn’t believe it. For years, she’d returned to the building every Monday night to leave £50 beneath his desk. “Why the money?” I asked. She wiped her eyes. “Because every Monday, when Richard was a little boy, I gave him £50 for his school expenses. I stopped when he became successful. He told me he didn’t need my money anymore.” She looked at the empty chair. “I promised him I’d never stop giving him something.” I felt a lump in my throat. Then she said something that made the room feel suddenly colder. “Did he ever ask you to clean the bottom drawer?” I shook my head. She pointed toward the desk. “Look inside.” The bottom drawer was locked. I fetched a key from the maintenance cupboard and opened it. Inside was a thick folder labelled OCTOBER 2015 — INTERNAL INVESTIGATION. The first page listed several suspicious transfers from the bank. The second contained the names of three senior executives. The third page had my name on it. I stepped back. “I’ve never worked in banking. I clean the offices.” Margaret looked at me carefully. “Your father did.” My father had died when I was eleven. All I knew was that he’d worked in an office before losing his job and moving our family into a smaller flat. I turned the page. There was a photograph of my father standing beside Richard Collins. Underneath it, someone had written: THE ORIGINAL WHISTLEBLOWER. I read the documents until my hands began to shake. My father had uncovered a scheme involving stolen customer funds. Before he could report it, he was accused of fraud and dismissed. The case destroyed his reputation. He died believing nobody had ever believed him. But Richard had kept the evidence. And three days before his death, he’d written a letter addressed to me.