Beadle's New York Dime Library, No. 601

Joe Phenix's Shadow: A Romance of the Seen and Unseen Albert W. Aiken's mystery serial opens in Washington Square, New York, April 1890. Park policeman Maginnis discovers the body of Abraham Rosengelt, a wealthy elderly Hebrew diamond-broker, stabbed to the heart while reclining on a bench. The autopsy reveals a peculiar wound—made by an instrument like a stiletto, no thicker than a knitting-needle, driven with anatomical precision, suggesting a killer with medical knowledge. Police superintendent and private detective Joe Phenix, recognizing the victim, immediately rule out robbery: Rosengelt's watch, chain, diamond ring, and forty dollars remain untouched. Phenix and the chief deduce the murder stems from private revenge rather than common crime, theorizing the killer was no stranger to Rosengelt but someone he knew. They speculate about the victim's wealth, his son and daughter who helped manage the business, and begin investigating who stood to gain from his death.