The moon illuminated the dark alley behind the old warehouse. Detective Johnson arrived, noticing the eerie silence that filled the air. He cautiously approached the lifeless body lying on the damp ground. The victim, a young woman, had multiple stab wounds on her torso. Blood pooled around her, a stark contrast to her pale skin. Johnson knelt down, examining the body for any clues or evidence. He noticed a small piece of paper clutched in her hand. Carefully, he retrieved it, unfolding the note with gloved fingers. The message, written in red ink, read: "I know your secret." Intrigued, Johnson stood up, surveying the scene for any witnesses.