The grandfather clock struck midnight as Detective Sarah Chen entered the Victorian mansion through its heavy oak double doors. Blood pooled beneath the crystal chandelier where billionaire tech mogul Harrison Blake lay motionless in his finest evening attire. His wife Eleanor stood frozen beside the marble staircase, her champagne glass shattered across the imported Italian tile floor. Twenty dinner guests huddled together in the adjoining parlor, their faces pale with shock and their voices hushed considerably. The butler, an elderly gentleman named Charles Whitmore, trembled as he explained how he'd discovered the body minutes earlier. Sarah noticed the French windows stood wide open, November wind billowing the silk curtains like ghosts in the darkness. A sterling silver letter opener protruded from Blake's chest, its ornate handle glinting under the chandelier's thousand crystal prisms. The detective knelt beside the body, careful not to disturb the crime scene while checking for any vital signs. No pulse remained in the man who had revolutionized artificial intelligence and amassed forty billion dollars before turning fifty. Sarah stood slowly and surveyed the opulent room, knowing one of these elegant guests was definitely a cold killer.