A famous concert pianist was found murdered in her dressing room right before a major performance. The room had three closed windows and one heavy oak door bolted from the inside. On the dressing table sat a metronome still ticking rhythmically, a glass of water, and an unsealed envelope containing a threatening letter. Detective Sterling noticed something impossible about the room's environment and deduced the killer had been there long after the door was bolted. What was it?
The metronome was still ticking.
Mechanical metronomes have a limited wind-up duration (usually only a few minutes to half an hour). Since the pianist had been dead for hours, someone had to have entered recently to wind the metronome.
About this riddle
Detective riddles are tiny mysteries. Look for the detail in the story that does not fit; it is usually the clue that solves the case.
Difficulty: Hard. More like this: Detective riddles with answers or try Truth & Lie Island for a different kind of puzzle.
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