The investigative team of Bertha Cool and Donald Lam is one of the more interesting ones in literature. Bertha is a large woman whose appetite for money exceeds all of her other cravings and Donald is a genius at solving crimes. Unlike other detectives, he relies on thought and anticipation rather than the power of firearms. While he is similar to Perry Mason in that he skirts the edges of the law, generating hostility from police officers, unlike the Mason stories, the hostility between the law and Lam is not as dominant. In this story, a client (Harry Sharples) asks for assistance in determining why the beneficiary of a trust (Shirley Bruce) that he co-administers is behaving the way she is. There are two beneficiaries, the other; (Robert Hockley) is a spendthrift who is always asking for more money. By the terms of the trust, it is possible for the relative amounts of the disbursement to be changed; however Shirley is willing to allow Robert to receive more money than she does. The story revolves around a necklace made from emeralds. The trust has major holdings in Columbia, specifically gold and emerald mines. The Colombian government has a monopoly on emeralds, so the output of the mine is strictly regulated. Things change quickly when the other trust administrator (Robert Cameron) is found stabbed to death. Lam and Sharples discover the body and Lam immediately suspects a set-up. What further confuses the issue is that loose emeralds seem to be present in abundance. Cameron has a pet crow that moves between two nests and Lam finds emeralds in both locations. There is a beautiful artist and her hotheaded mother, who tries to knife Lam. With so many characters having their own contributions to the mystery, there are more than enough suspects to obfuscate the culprit. What I liked most about the story is the description of Lam's trip to Columbia. He interacts with Colombian authorities on an equal basis. There are no aspects of anti-American feeling in the Colombians and Lam treats them as intelligent equals rather than hicks. Bertha Cool fills the role of the ugly American, insulting everyone in sight. Lam learns all he needs to know while in Columbia and returns to the United States. Once he gets back, he unmasks some false relationships and exposes the murderer. It was not the person that I suspected, although there were clues distributed throughout the story. This is one of the better Gardner mysteries, written under the pen name of A. A. Fair. Lam is the thinking person's detective, he solves the case without firing a shot, punching a nose or engaging in deceptive actions.