The Case of the One-Eyed Witness

I am currently reading The Case of the One Eyed Witness by Perry Mason. This is the first time I have read a mystery novel n a long time, so I was interested to see how I liked them now. The story has several themes going on in it at the same time, which make it slightly hard to follow but interesting at the same time. The first mystery theme to enter the story has to do with a frantic woman who calls Mr. Mason late at night claiming that he is to receive a package shortly and that when he does he must deliver it to a man named Carlin. Once the phone call is over, Mr. Mason sees a distressed Cigarette girl in the restaurant he is in, and decides to confront her. He finds out that the young woman had her daughter take in from her by her husband, and can not find the two any where. The third theme that really takes effect in the story is after Mr. Mason wishes the cigarette girl well and leaves to find this mysterious Carlin. He is eagerly invited into the man's house and over a cup of coffee in the late night, explains to Carlin the interesting phone call from the frantic woman, and a message that she wanted him to here, "you are to get a new partner." The incident means nothing to Carlin and he claims he does not have the slightest idea what this woman is talking about. All three conflicts appear to have nothing in common, but I believe not. I have a feeling that they are very much all interwoven. Perhaps Mr. Carlin is not admitting everything that he knows; and the cigarette girl is involved without even realizing it? Often in mystery novels, all of the little stories wind up to one larger conflict. Hopefully however, I can deduce more of the mystery over the coarse of me reading, this and try and discover the mystery along with the detectives!