The body of Herbert Endicott is discovered by his wife at 8:37 PM, dead in his walk-in closet. The circumstances seem suspicious but there is no evidence of foul play, so Lieutenant Valcour, New York's most astute investigator, orders an autopsy on site. The doctor discovers a faint heartbeat and, with an injection of adrenaline, Endicott is alive again. But just a few hours later, he has been shot dead-this time for good.

From this puzzling set-up, an atmospheric and tense mystery ensues, with Valcour's research turning up more questions than answers. Before twenty-four hours are up, the solution will be uncovered.

Fans of S.S. Van Dine's Philo Vance will appreciate the introspective Lieutenant Valcour, who makes his series debut in Murder by the Clock.