Walter S. Rogers

"Drop case or else danger for you and your family." This warning addressed to Fenton Hardy not only alarms the famous investigator and his detective sons, but also puzzles them, because Mr. Hardy is working on more than one case. Which one prompted the threat? When more ominous warnings follow, Frank and Joe suspect there is a link between the counterfeiting case they are investigating and a secret case their father cannot discuss since it involves...