"The FBI watched what Stout wrote and somehow turned his fiction into suspicious fact. Because, for example, of a story that appeared in the May 1940 issue of American Magazine called "Sisters in Trouble," he was labeled what might be called "prematurely anti-Nazi." A highly imaginative document from Los Angeles (correspondent's name censored) to the FBI's Communications Division in Washington claimed that the story was "either a deliberate attempt to convey a meaning other than the solution of a mystery story — or else the whole thing is full of coincidences.
The FBI closely monitored what Stout wrote and eventually linked his fiction to suspicious facts. For example, due to a story featured in the May 1940 issue of American Magazine titled "Sisters in Trouble," he was labeled as "prematurely anti-Nazi." A document from Los Angeles (with the correspondent's name redacted) sent to the FBI’s Communications Division in Washington suggested that the story either had an unintended meaning or contained numerous coincidences.