First published in 1941, this is, to my mind at least, one of the least successful of the Perry Mason novels. But then, in a series that runs to eighty-five books, I suppose there's bound to be a clunker now and then.
A murder may have been committed on the ground floor of an apartment building. (There's no body, but there is a lot of blood and Lieutenant Tragg and the rest of the force are treating it as a potential homicide.) The guy who lives in the upstairs apartment is an invalid and a recluse and he does not want to get involved in the investigation. So he hires Perry Mason to come over and shield him from the cops. One would think that, if you're attempting to deflect attention away from yourself, it would NOT be a good idea to have the city's most famous defense attorney standing in your living room when the cops come calling, but that's just my humble opinion.
It takes a long time to determine if a murder actually has been committed, and in this case, Perry will spend no time in court at all. Rather, he will spend the entire book running around attempting to decipher a plot that makes absolutely no sense at all. It involves a suspicious boarder, a house with a lot of mysterious doors leading here and there, a nosey spinster, guys wearing wigs, people running guns in China, and other people scratching coded messages on the lids of tin cans. At one point, Perry is attempting to explain part of what is happening to his secretary, Della Street, when she throws up her hands and says, "I'm sorry, Chief, but I'm all topsy turvy!" To which, the reader can only reply, "Don't worry, Della, you're not the only one..."
Of course, Perry will ultimately get it all sorted out and given a couple of critical clues, most readers will actually get there ahead of him. Still, this book is something of a mess, and a person probably would not want to spend a lot of time attempting to make sense out of it. It's much better just to sit back and let Perry, Della and Paul go about their business and enjoy the various exchanges that take place.
My favorite part of the book occurs a little over halfway through. A little after five o'clock on a busy afternoon, Perry suddenly decides that he needs to make a quick trip to San Francisco. From downtown L.A., he calls the airport and books tickets on a flight leaving at six o'clock. He then calls Della and tells her to meet him at the plane. Della replies that she'll just take time to put on some makeup and then head on out from downtown to the airport. Perry tells her to "Make it snappy," and hangs up. Even though the late afternoon rush is on at the airport, they both make it and are relaxing in their seats when the plane leaves on time at six o'clock! Those must have been the days...