A terrible spy mystery involving a Nazi spy and some money-grubbing people. A briefcase belonging to Gwenn, who has been knocked unconscious, is found at the scene of a plane crash. In it are four wills indicating where large sums of money willed to Gwenn are kept. Hasso's husband is killed while trying to get the money, and she teams with Craig to finish the work. Just when they are about to succeed, they are confronted by Gwenn, who reveals that he is a Nazi agent trying to get the money and escape to Germany. The two end up capturing Gwenn and they turn the money over to the government.