Winter 1778 . As the Continental Army settles into its Winter Camp, Faith Clarke travels north with Lady Washington to help out. Despite her joyous reunion with Will McKay, she is troubled by what she sees. The camp is plagued not only by cold but by inadequate shelter and shortages of food and clothing. Joined by her older sister, Hannah, a refugee from occupied Philadelphia, the women work to help the struggling camp.

Whispers permeate the camp of an unseen enemy who is killing soldiers and taunting Washington after each death. The General asks colonial spy Jeremy Butler and Will to investigate.

Faith discovers the body of an officer hanging in the forest, strung up by his own scarf While some believe it is suicide, Faith believes something far more grim has occurred. Aided by Hannah, the women seek answers as more bodies are found.

When Butler shares that Washington receives a macabre poem describing the deaths plus some not yet committed, Faith realizes they are running out of time. Trapped by the weather within the camp, they have to pursue all leads in order to unmask the enemy within.