无法投递又无法退回的信件

German/American art dealer Martin Schultz (played by Paul Lucas) returned to Germany during the outbreak of World War II, adopting a Nazi propaganda philosophy and refusing to protect his son Heinrich Schultz (played by Peter Van Eyck)'s Jewish fiancee, Greesel Eisenstein (played by K.T. Stevens), who has been staying in the United States to run a family business