Terry Pratchett’s latest Discworld novel brings back one of his recurrent characters, Sam Vimes, Duke of Ankh and Commander of the City Watch, in a new setting: his country estate, two days’ coach ride from Ankh-Morpork. But, naturally, he isn’t there for long before he acquires a crime to deal with. This is classic “cozy” mystery terrain, the sort associated with Agatha Christie and Dorothy Sayers, with a houseful of servants and surrounding houses full of gentlefolk, a natural environment for Vimes’s wife Sybil, who is the very personification of Old Money. But Vimes himself is barely even New Money, and his usual sort of mystery plot is hardboiled, noir, or police procedural. The conflict between the two is one of the big drivers of the comedy in this story.

But there’s more going on here than comedy. The country gentlefolk turn out to be every bit as capable of corruption and wickedness as any noir villain. Sam Vimes doesn’t just face elegant drawing-room conversational sparring, but physical threats to his life.

And the source of these plots? Here’s where the libertarian theme emerges: Like some of the wealthy rural families Jane Austen wrote about, these prosperous gentry are making money off the the enslavement and abuse of one of the Disc’s minority races. Since this is a fantasy novel, the race in question is Pratchett’s version of goblins. Pratchett gives them a detailed and peculiar culture focused on beliefs that seem religious to other races, though goblins themselves don’t regard them that way. He also makes a point of their distinctive cognitive modalities and language, in a fashion that makes me think of John W. Campbell’s classic definition of an alien as “a being that thinks as well as a human being, but not like a human being.” None of this is noticed by other races, which drive them onto marginal land (or under it!), murder them, or enslave them—in an ironic reversal of history, shipping them off to work on plantations in the Disc’s analog of Africa.

Vimes gets drawn into this when agents of the slavers try to frame him for murder, using a goblin woman as a convenient source of blood. At this point he turns back into a policeman with a crime to investigate, or a whole series of crimes—indeed, in Vimes’s view, slavery as such is a crime, and he sets out to bring the rich and powerful people who commit it to justice, whatever the price. In the process, he recruits a goblin as a police officer, setting goblins on the same path to equality as trolls, dwarfs, werewolves, golems, and a long list of other Discworld races. The action this leads to is some of the most dramatic Pratchett has written, including a terrifying riverboat journey barely ahead of a catastrophic flood. Vimes is abetted, in proper “cozy” style, by his butler, Willikins, who turns out to have various skills and talents that aren’t usually required of butlers.

At the same time, Pratchett shows the role of cultural and intellectual change in bringing an end to slavery. Roles in this are played by Pastor Mightily Oats (first seen in one of the Lancre novels) and by Miss Beedle, an author of popular children’s books (including many of Young Sam Vimes’s favorites) and a classic socially marginal figure. But, above all, Sybil Vimes emerges as a key figure on this side of the story, changing the minds of many of Ankh-Morpork’s elite, and making it possible to change the law.

In other words, this novel continues Pratchett’s recent use of the Discworld to reexplore the emergence of modernity as a theme. And, like Neal Stephenson’s Baroque Cycle, Pratchett’s novels view modernity as including not merely technological change, but changing values and institutions—changing in a direction libertarians will want to cheer for. I think this novel is one of our best candidates for this year’s Prometheus Award, and I encourage members of the LFS to read it.