An elderly woman came to Perry Mason for consultation (I sound exactly like Al Bundy from Married with Children describing the plot of the books of the series, do I not?)
Anyhow, the woman thought her favorite granddaughter Sylvia was in big trouble. Sylvia had gambling addiction. She wrote several IOUs (documents acknowledging debt in simple terms) to cover her debts in a casino. Her husband was in the middle of divorce proceedings and he would have loved to get his hands on these documents as a proof she cannot handle the money and thus to obtain a complete custody of their kid. As you can see divorces were as messy almost 100 year ago as they are now.
Add to this big money of the family and you will understand that the IOUs became much more expensive to all parties than just their face values considering the fact that the casino owners were not above a little blackmailing; they were just waiting for the highest bidder. This is where Mason came in: he was to procure these documents as discreetly as possible. He concocted an elaborate scheme to get them for exactly their real price, but an appearance of a dead body really crumpled his style.
As a result Mason had to defend his client against a murder charge. Everything seems to be against him, but fear not. He not only beat the odds and cleared the innocent person's name, but also paved a way for her to get even more money to gamble away as nobody cared about Sylvia's addiction.
It was a good mystery which kept me guessing until the end. Even Mason trying to untangle it had to put himself in a very tight spot; probably the worst he has been so far. We also get to see interesting personal interactions between the three major recurring characters: Perry Mason, Della Street, and Paul Drake as well as some glimpses at the way Drake's detective agency operates. A usual rating for a book of this series applies: 4 stars.