From The Perry Mason TV Show Book (Revised)
Perry is approached by a young woman named Dorrie Ambler who wants him to verify her identity. A seedy private eye has been paying her to frequent certain places around town and Dorrie thinks it’s because she resembles someone else. Paul learns that this is true: Dorrie looks like a spoiled heiress named Minerva Minden. After some checking, Perry discovers that Minerva was supposedly involved in a hit-and-run accident, and it looks as though Dorrie is being used to prove that. But why?

Blackmail. At least that’s what it looks like. But when the blackmailing private eye is killed, Perry learns the truth. Dorrie Ambler is Minerva Minden. She wasn’t hired by the dead man, she was being blackmailed by him. The question is: Who is the dead woman burned beyond recognition in the car accident but identified as Dorrie Ambler?