Trying to help a woman in distress, World War I nurse and accidental sleuth Bess Crawford learns that no good deed goes unpunished.

When battlefield nurse Bess Crawford returns from France for a well-earned Christmas leave, she finds a bruised and shivering woman huddled in the doorway of her London residence. The woman has nowhere to turn, and propelled by a firm sense of duty, Bess takes her in.

Once inside Bess' flat, the woman reveals that a quarrel with her husband erupted into violence, yet she wants to return home - if Bess will go with her to Sussex. Realizing that the woman is suffering from a concussion, Bess gives up a few precious days of leave to travel with her. But she soon discovers that this is a good deed with unforeseeable consequences.

What Bess finds at Vixen Hill is a house of mourning. The woman's family has gathered for a memorial service for the elder son, who died of war wounds. Her husband, home on compassionate leave, is tense, tormented by jealousy and his own guilty conscience.

Then, when a troubled houseguest is found dead, Bess herself becomes a prime suspect in the case. This murder will lead her to a dangerous quest in war-torn France, an unexpected ally, and a startling revelation that puts her in jeopardy before a vicious killer can be exposed.