Mr Keen is called to a factory for his next investigation. A war factory has gotten a threat, and one of the employees has disappeared. Is this a matter of a personal dispute? Or does it have to do with sabotage, and national security? Red flags start flying for Mr. Keen, then he gets a hot lead and a strange clue.

Sort through the clues, suspicious characters, and follow Mr. Keen as he ties all the loose ends together. Just who is who in this mystery of embezzlement, blackmail, and stolen identities?