A summary of bada-BOOM! The third book of the Hamlin Park Irregulars series by Wally Duff A woman hopes to reestablish herself as an investigative journalist by chasing a story about suspicious suicides in this third installment of a series. Chicago stay-at-home mom Tina Thomas lost her reporter job years ago when she disregarded an FBI order. But she’s always looking for a story to redeem herself, and MidAmerica Hospital surgeon Dr. J. Randall Fertig may be the answer. Fertig claims he performs an operation that cures all his patients of breast cancer. As he’s inexplicably mum on specifics, the Illinois Department of Public Health demands MidAmerica appoint a committee to investigate his results. Tina’s potential story only gets juicier when a physician from that committee dies in a one-car crash—an apparent suicide. Later, a second MidAmerica doctor supposedly dies by suicide, and Tina surmises the deceased was also a committee member and that Fertig, for whatever reason, is killing the physicians to keep them quiet. She’s likely on the right track, as an armed man tries intimidating her to drop the case, which soon involves additional mysterious deaths. Luckily, Tina has ample help from a couple of local detectives as well as a group of friends colloquially known as the Hamlin Park Irregulars, each as exuberant as the former journalist. Duff’s (Deja-BOOM!, 2018, etc.) character development is exceptional, as he masterfully handles myriad players. In this novel, that unfortunately means some recurring characters, like Irregular Cassandra “Cas” Johnson, have only occasional appearances. But others, particularly whip-smart DS Janet Corritore, shine in the spotlight. Tina’s investigative technique is delightfully curious; she unabashedly violates laws, from breaking and entering to the gun she carries that may or may not be registered. It’s all part of a tight narrative that runs at full tilt, as abundant short chapters accommodate the brisk scenes. For this book, Duff has honed his sharpest mystery yet: The big reveal is a doozy, and the inevitable wrap-up makes it even more enticing. Extraordinary characters and a top-notch twist make this a standout mystery