A guy came to Perry Mason's office with a very unusual problem. To explain it I (and any reader of this installment) had to learn a lot about artificial eyes in US of early thirties.
The info is not boring by the way. Anyhow, we are talking about high quality glass eyes made by very rare specialists. To fool people into thinking both of your eyes are fine and natural, people with one eye missing - lost in an accident for example - had to use several artificial ones through the day. In the morning one has to use an eye with pupil dilated, in the evening the one with narrower pupil. A curious case would be time when your working eye becomes bloodshot - as a result of strain, or alcohol consumption.
This bloodshot artificial eye was the reason for a visit to a lawyer. Somebody stole this particular one from the set the guy had and substituted a very crude (we call it mass-produced these days) one. As the high quality ones are easily traceable, the guy was afraid somebody would use the stolen eye to frame him for something. He paid Mason cool hard $1500 in cash as a retainer to protect him from such frame. We are talking about the year 1935 when this was serious chunk of money.
No sooner the guy left as another couple came to Mason for a consultation with a seemingly unrelated problem. Coincidences however almost never happen to Perry Mason and fairly soon an apparent suicide connected all of Mason's clients. The victim has the stolen eye in his hand. There were way too many guns around him.
Now Mason had to work for his money, hard.
This novel is the first one where Mason's traditional archenemy in the courtroom appears - District Attorney H.M. Burger (for an amusement try to pronounce his full name aloud). The guy will fight Mason from this point on to the rest of the series with some minor exceptions, always losing. He was not Mason's biggest fan, and the reason for this becomes apparent in here: the latter made a complete fool of Burger right in the courtroom. Mason tried to sweeten it though.
Another enemy of Mason - Sergeant Holcomb of the Police Homicide Division - gets to act heroically earning grudging respect from the lawyer. This installment finally settles into the pattern which the rest of the series follows with Mason's trademarked brilliant cross-examination of witnesses in the court.