Series numeration from www.goodreads.com.

"Originally published in the United Kingdom as Hush Hush by Century, a division of Penguin Random House, 2019"--Copyright page.

"Top cop. Devoted sister. Now Inmate 3329. But prison bars won't stop Harriet Blue from seeking justice for the murder of her brother. Prison is a dangerous place for a former cop--as Harriet Blue is learning on a daily basis. So, following a fight for her life and a prison-wide lockdown, the last person she wants to see is Deputy Police Commissioner Joe Woods. The man who put her inside. But Woods is not there to gloat. His daughter Tonya and her two-year-old child have gone missing. He's ready to offer Harriet a deal: find his family to buy her freedom"--