I look into baby Fern's crib, and my heart pounds. I'm her nanny, I was supposed to keep her safe. I hear the police downstairs, and the next words I hear make my legs buckle underneath me. 'It was the nanny. She's guilty'. When I first walked into Jake and Megan's immaculate home, I felt totally at ease. Sitting in the crisp white living room, they held hands and talked lovingly...