Because it likely appeared as a "magazine novel, complete-in-this-issue," I'm taking certain liberties here with the definition of "novel" but so be it. Corkscrew is a novelette (in pulp terms) or a short novel (in literary terms). It was written at the time when hardboiled detective fiction was sometimes cast as western fiction. Black Mask thrived on this fusion early on. One of Hammett's best stories, "The Killing of Dan Odams," is in fact a western.
Corkscrew is the name of a lawless town in Arizona early in the last century. There aren't many farmers here because farmers are afraid to settle here given the violence.
Corkscrew has telephones and automobiles but it is otherwise of the old west. Our man was sent here undercover by his detective agency to try and resolve the town's chief problems one of which, timely given today's politics, what to do about all the illegals crossing into the United States. He will be the new deputy sheriff, the real sheriff being elsewhere. But the man who sent for him told everybody that he was coming and when to expect him. Some undercover. Hammett uses wry bits of business throughout this long story and they give it the bite of real life. Sometimes humor makes things sound truer than melodrama, at least for me.
The first set-piece is one of Hammett's finest moments, an extended and bitter poker game in which Slim Vogel and Mark Nesbit try to close each other out. Hammett gets everything just right--the men standing around the table, the other card players dropping out just so they can watch the rivalry and the escalating name calling between the two players. At first the names land like punches but there are so many of them and they come so quickly that Hammett slyly turns them into a comic comment on machismo. Monty Python later did something very much like this with in the insult-hurling Frenchman on the battlement.
The heart of the story is a murder mystery that is one of Hammett's trickiest puzzles. He hits us wham-bam with two murders in just a few pages and so we have to recalculate everything we've assumed previously. The prose is impeccable. Sometimes Hammett is a little too spare for me but here he's giving us this strange, dusty little town in careful, vivid detail.
This is one of those pieces of work that you can both enjoy and admire. You just stand back and look at a master do his work.