1862: The Union holds Baltimore, but this city, with its southern attitudes and divided sentiments, is a port of enormous potential value to the Confederate cause.

Defending Baltimore is a man disdainfully called the "Black German." Branden Rolfe, a European revolutionary, fled the oppression of his home in Austria and now serves freedom as the city's Union Provost Marshal. When Rolfe learns of the Sons of Liberty, a secret group of secessionists determined to capture Baltimore, he fears their success could alter the course of the conflict. The war has already separated him from his adopted children and the woman he has learned to love. Now, the threat of the Sons, led by the clever, dedicated Langdon Everett, becomes a thorn in his side as the group gains supporters and amasses a considerable cache of weaponry and explosives. Rolfe feels official pressure and a personal need to stop them at all costs, even to the point of risking the life of his love, who volunteers for dangerous duty undercover. . .

Eden Farnswood comes to the Sons through her new friend, Holly DeMornay, the cousin of their leader. Appalled by the terrible human cost of war, young Mrs. Farswood is a widow who set out to become a nurse but has found a new mission in the Sons of Liberty. Torn by bitter memories and divided loyalties, Eden finds it too painful . . . and too dangerous . . . to share her secrets with anyone, not even Holly, her closest friend.

As Rolfe's web of spies closes in on the Sons of Liberty and Langdon Everett, the fates of Baltimore and of Eden Farnswood hang in the balance. In Baltimore, where North and South meet, love and war conspire so that, win or lose, there will be a terrible cost either in lives or by the betrayal of the human heart.