It's the 1940s. World War II is raging and a Jewish refugee in England is working on a substance that could give Britain an edge in the war. Michael Harsch has worked for years trying to perfect his work and now he's finally ready to turn it over to the War Office. He calls Sir George Rendal to let him know of the success and makes arrangements to turn his findings and all his notes over the next day. It's an appointment that he'll never keep. Harsch goes to the church to relax with music and is later found dead beside the organ. And a German pistol is found beside him. The door is locked and key is in his pocket. There are other keys--but they all seem to be accounted for. A coroner's jury brings in a verdict of "suicide while the balance of his mind was disturbed." But Harsch's friends don't believe it and Janice Meade calls in Miss Maud Silver to find out the truth. Miss Silver's years as a governess have given her plenty of insight into human nature.