The grandfather clock chimed midnight as Detective Sarah Chen stepped into the dimly lit mansion's grand foyer below. Blood pooled beneath the crystal chandelier where prominent businessman Marcus Whitfield lay motionless on the marble floor tonight. His wife Eleanor stood trembling near the ornate staircase, her silk evening gown stained with crimson drops. The butler had discovered the body twenty minutes earlier while making his usual rounds through the estate. Three dinner guests remained in the drawing room, their animated conversations from earlier now replaced by silence. Chen noticed the study door stood ajar, papers scattered across the mahogany desk inside the locked room. A wine glass lay shattered beside the victim, its contents mixing with blood on cold stone. The detective pulled on latex gloves and knelt beside Whitfield, observing the single stab wound carefully. Thunder rumbled outside as rain began pelting the tall windows, trapping everyone inside until morning came. Chen stood slowly and surveyed the scene, knowing one of these people had committed murder.