The old mansion stood silent against the dark stormy night sky. Detective Morgan arrived at the scene precisely at midnight sharp today. Rain hammered the gravel driveway as she stepped from her car. A single light flickered behind the curtains of the upper floor. The butler waited at the door with a pale haunted face. "Someone has murdered Lord Ashworth in his private study," he said. She followed him through the hall lined with ancient family portraits. The body lay crumpled beside a heavy mahogany desk in shadow. A letter opener protruded from his chest stained dark with blood. Every guest at dinner tonight would now become a prime suspect. Morgan knelt beside the corpse and studied it with careful eyes. The grandfather clock in the corner had stopped at nine fifteen. She noticed the window was locked firmly shut from the inside. No one could have entered or escaped through that sealed room. The killer was still somewhere inside this house among the guests.