From award winning author Peg A. Lamphier comes the fourth installment of her Kate Warne Civil War Spy series. As if Pinkerton Detective Kate Warne doesn't have enough to do, what with Confederate spies running amuk in war-time Washington, an old case comes back to haunt her. Five years a Black Widow killer disappeared without a trace. Now it looks like the nefarious lady serial murderer is back and getting ready to kill again. The tricky part of the investigation lies in establishing the Black Widow's identity. The client wants the Pinkerton Detective Agency to discredit a lady spiritualist who has romantically ensnared his boss. At first Allan refuses the case. He has a long-standing policy of not taking 'marital' investigations, but when the client's description of the mysterious temptress rings a bell Pinkerton sends for Kate. He might have stumbled upon the Black Widow.Kate retraces her investigative trail, hoping to uncover details that will link the woman who killed her father and two husbands to this lady spiritualist. The new investigation pushes Kate to confront the investigative mistakes she made when she was new to the detecting business. What she learns forces her to think about the Black Widow case differently. Alone in wintery upstate New York, separated from her Washington friends and missing Army Captain George Hazzard, Kate must confront the social norms that push some women to violence. Cold and alone, she must ask, is murder ever justified? And do some men need murdering?