The clock struck midnight as the mansion's grand hall echoed with the sound of a distant, haunting melody playing softly. Detective Harper arrived at the scene, his trench coat flapping in the cold wind, eyes scanning for any immediate clues. A shattered vase lay on the floor, its porcelain pieces glinting under the dim light, hinting at a recent struggle. Lady Evelyn's lifeless body was sprawled on the Persian rug, her eyes wide open, a look of terror frozen. The guests, dressed in their finest attire, whispered among themselves, their faces pale, trying to piece together the night's events. A blood-stained letter opener was found near the fireplace, its ornate handle glistening, suggesting it was the murder weapon. The butler, Mr. Collins, stood by the doorway, his hands trembling, eyes darting nervously, as if hiding a dark secret. Detective Harper knelt beside the body, examining the wound, his mind racing with questions, searching for the elusive truth.