The serial killer at dawn

Previously

…He stared at the words, the ink drying under the lamp. Then a knock came at the door. Trevor stood, his heart quickening. He crossed the room, his hand hovering over the knob. "Who is it?" No answer. He opened the door. The hallway was empty. But on the floor, there was an envelope. His name written on the front in neat, precise handwriting. He picked it up, his fingers trembling. Inside was a single sheet of paper, folded once. It read: Dear Trevor, You think you've won. But you've only just begun. —The Collector