In The Case of Murder and the Jewel Thief, Mr. Keen receives a mysterious phone call from Carl Rollins, a jewel thief infamous for his cunning heists. Known as Kansas Carl, Rollins is wanted by the police across multiple states. He urgently requests a meeting with Keen, hinting at a significant issue that requires the investigator's expertise. However, just as he begins to explain, gunshots ring out, and the call abruptly ends, prompting Keen and his partner, Mike Clancy, to rush to Rollins' apartment.