Gray Waters. SECRETS OF THE BLUE AND GRAY series featuring women spies in the American Civil War, #3

Stop a conspiracy or protect the friend who means the most to her.she can't have both. March 1864. Union spy Hattie Logan has barely recovered from her last assignment when she's sent after Mollie Pitman, a former Confederate spy who may be playing exactly the game Hattie once played herself. Trusting her could save lives. Trusting her could also get Hattie killed. Mollie leads her to the Sons of Liberty, a secret network of Northern traitors plotting to seize control of entire states, arm a shadow army, and break thousands of Confederate prisoners out from behind Union lines, crippling the war effort from within.
What Hattie uncovers next is worse: one of the men leading the group is no stranger. Exposing him could cost Hattie the one friendship she's never had to guard or explain herself to. Hattie is also wrestling with a devastating truth about a man she loved and lost. Lieutenant John Elliott has been patient with her. But letting him in means letting go of what she's held dear, and with the people closest to her now caught in the crossfire, she is running out of time to decide.
Gray Waters is the most action-packed installment yet in the Secrets of the Blue and Gray series, for readers who love a heroine who trusts no one but herself, a conspiracy with real teeth, and a love she has to choose to let herself have, perfect for readers who loved The Mitford Affair and The Widow of the South. Book Three of the Secrets of the Blue and Gray