As World War II winds to a close, Europe's roads are clogged with twenty million exhausted refugees walking home. Among them are Jacob and Sarah, lonely Holocaust survivors who meet in Heidelberg. But Jacob is consumed with hatred and cannot rest until he has killed his brother's murderer, a concentration camp guard nicknamed "The Rat," also from Heidelberg. Jacob and Sarah fall in love, for a time, the only Jews in the whole city. As Jacob waits for the concentration camp guard to come home from the war, he is beset by doubt. If he fulfills his oath and kills the guard, he will undoubtedly be caught, and Jacob and Sarah's new life will die as well. At the same time a secret hit team from the British army's Jewish Brigade is assassinating former SS officers hiding out in Germany. Jacob's Oath is both a love story and a riveting thriller with a very tricky ending indeed.