I'm assuming that you've all seen the hilarious film version made a year after this book was published, so I hardly need tell you of the plot. But there is more in this book then could be shown in a Code movie. Dashiell Hammett's prose is quick and to the point, jumping along through the plot at breakneck speed without any unnecessary subplots or descriptions in order to pad it out. The novel also gives us more insight and developments into the characters and suspects then the film could have had time to go into, as a result the characters are better developed so that the reasons for the murders and the revelation of the murderer is more exciting in print form.
However, what the book lacks is the banter between Nick and Nora that we loved so much that it spawned five more Nick and Nora and Asta films. And also Nora doesn't drink as much as the film version does, which is a darn shame. Although it would have been nice if Hammett had developed more Nick and Nora detective stories, I don't think I could have imagined then not acting and sounding like William Powell and Myrna Loy and their relationship and detection methods do play out better on the screen then in print and wisecracks are hard to be funny in prose since it removes comic timing and timing is what made the Thin Man series great.
I like the breathless style of Hammett's writing and he's one of my favourite American detective writers. Although he's known for writing hard-boiled detective stories, I don't think that The Thin Man falls into this category because Nick is married to Nora and not sitting alone in his office with a bottle of scotch.