An ordinary raincoat finds its way to the Black Museum, and we learn about the crime that put it there. Robbers in white cloth masks took no jewelry, and the only victim was the young man shopping for a wedding ring. How will the anonymous, shabby raincoat link the robbers to the scene? The pistol used in the crime is in the pocket, but it was a stolen one. A glimmer of hope comes when the coat was traced to certain possible shops, and the tedious police work begins. X