The River Rat Murders presents the first part of the diary of Caroline Case, a Wabash Valley Madame, during Prohibition. After the murder of her friend Alec in 1921, Caroline becomes an amateur but extremely resourceful detective. She and her mysterious new friend, Hannibal Jones, her "girls" and an odd assortment of local characters solve five murders. They get no help from the authorities, who are on the take from gangsters who control the booze trade in the Valley.

Caroline, Hannibal and their friends call themselves "The River Rat Detective Agency." As they solve the murders, they become involved in the war between Al Capone and the North Side gang over control of the booze trade. There are shootouts, kidnappings and daring rescues.

Over time (1921-1928), Caroline evolves from humble beginnings into a sophisticated, liberated woman. She accumulates wealth from investments in speakeasies, roadhouses and upscale salons. She uses her money to help her friends and to invest in legitimate businesses. After the fifth murder and an attempt on her life, she and Hannibal escape to their first adventure outside of the Valley.

In 1928, just before the crash of the stock market, Caroline and Hannibal solve a sixth murder, this time at a high-end resort in Florida. This murder relates back to murders in the Valley and to Al Capone, who has his vacation house at 93 Palm Island, Miami Beach, Florida. At the end of the story, Capone lifts the bounty on Caroline, and she and Hannibal are off to new adventures.  

In this second Wind Grass Hill murder-mystery, Frank L. Gertcher lets Caroline Case tell her own story of booze, gang wars, love and adventure. Although fiction, Caroline’s story rings true to the fascinating history and colorful characters who lived, loved and died in the bawdy towns along the Wabash River during the heyday of Prohibition. More murder mysteries will follow, as Caroline and Hannibal continue their adventures!