The mansion loomed in darkness. Rain pattered against foggy windows. Inside, guests mingled and laughed. Champagne flowed freely all night. Suddenly, a scream pierced air. Lights flickered, then went out. Panic spread through the crowd. In darkness, a thud sounded. When power returned, horror reigned. A body lay on floor. Blood pooled around the corpse. Detective Sarah Evans arrived swiftly. She surveyed the grim scene. "Nobody leaves," she commanded firmly. The investigation had just begun.