Nora Marsh has lived with the burden of a father who's been branded a traitor. She has tried to keep their inn, the Cat and Mouse, running smoothly, but her father's depression and drinking after his return from the World War II European front has made life difficult. Her life begins to further unravel when a new border, Daniel Cavell, turns up missing. Kate Sherwin, the local Civil Defense warden, and Cavell's mother, Ruth, begin a search which ends when his body is found in the window seat of the inn's living room. Kate has long suspected Nora's father Harry of being a spy and the death adds fuel to her suspicions. Harry Marsh may well be "The Cat," a notorious Nazi spy said to be somewhere on the East coast. Nora, torn by her love for her father and her love for her country, finds horrifying evidence that her father has been communicating with the Germans and may be involved in a plot to assassinate President Roosevelt. But can she be sure? A noose inevitably tightens around Nora who must somehow decide whom she can trust...if anyone.