Hans is an old soldier, a refugee from post-war Germany. Patrick Riordan befriends him and learns his story. When the old man is arrested and charged with war crimes in the camps in Poland, Patrick and his father Jack set off for Europe to find his missing sister to prove his identity. Meanwhile, the real criminal has been living in Florida. He flees after being recognised by a camp survivor and goes to ground. In Europe, a group of old Nazis try to stop Jack and Patrick finding the truth and exposing the real criminal, They send men to kill them and the sister they find. They have not bargained on a man like Jack Riordan, and their attempts fail. Their activities bring them to the attention of the Israelis who have hunted them since the war's end. Will they save their friend, or will the real criminal be brought to justice?