Now this is more like it! John Hornor Jacobs concludes his trilogy of cowboys and Romans with style and panache, picking up the pace, tightening the narrative, and never losing the joy of pulpy adventure even as he delivers more complex characters and greater depth in this alternate world. As Infernal Machines begins, longtime partners Fisk and Shoestring have just barely made it out of a demonic attack on Harbour Town, the equivalent of a nuclear detonation, complete with flash burns on people and animals that were many miles away from the explosion. Meanwhile, his wife Livia and her sister Cornelia are on their way back to Rume to face the imperial displeasure caused by their failed embassy to far Kithai. Things are looking bad for our heroes, which means that they are about to get worse.

Jacobs tells the story in alternating first-person narratives, with Shoe continuing in the role he has played since the beginning of the trilogy, and Cornelia stepping in as a fully fledged narrator in the third book. In the second, Foreign Devils, she had been an epistolary narrator, writing back to Fisk via a sort of demonic telegraph. In the current book, imperial orders ban her from using the device, leaving her with the habit of relating what has happened to her, leaving readers with a new narrator, and leaving Fisk with considerable anxiety about why he has suddenly stopped hearing from his wife who is half a world away.

Jacobs speeds up the action with short initial chapters, each one ending in a small cliffhanger and getting a set of characters deeper into trouble. Fisk and Shoe are in the odd-numbered chapters; by the end of their third appearance, they have laid an ambush, barely survived a shoot-out with the renegade engineer Beleth and his demonic minions, and been forced to join a band of dvergar who have their own ideas about what to do with Rumans and the half-dvergar like Shoe who work with them. Livia and Cornelia have the even-numbered chapters, and by their fourth appearance, they have returned to Rume, been told that the emperor has decided husbands for both of them (imperiously dissolving Livia’s marriage to Fisk without further thought), escaped their family’s villa with an infant in tow, confronted the emperor’s praetorian guard who had come to Kithai with them, fought him, and accepted his help in making their escape. In their next chapter, they resolve to steal a demon-powered navy ship to make their way back to Occindentalia.

Eventually the breakneck pace slows a bit, but only to give greater depth to the characters and the conflicts that they are smack in the middle of. War has come, and not only to Occidentalia. After burning Harbour Town, the Madierans look to use their armies and their superior seapower to banish the Rumans from the continent entirely. Across the Western Ocean, the Madierans’ newfound knowledge of demonic possibilities will bring the war home to Rume in devastating fashion.

Fisk is a man of the Hardscrabble Territories, but he had a full life in Rume before he lit out for the west, and parts of that life catch up with him in Infernal Machines. His commission to capture Beleth grows into a larger role, as Rume’s position in Occidentalia grows desperate. Shoestring helps him make contact with dvergar bands who mean to assert their own interests while the great foreign powers make war. More importantly, Shoe has gained new insight into the nature of the vaettir, the fearsome indigenous giants of the new world. They have no love for the Rumans, but the demonic terrors the Madierans are unleashing may be even worse.

Livia is a woman of Rume, shaped by the journey shown in The Incorruptibles, and her resourcefulness comes to the fore as she is determined to escape the emperor Tamburlaine. Cornelia, who started as a spiteful viper in the first book, has matured into a determined fighter and quick study of machines even while retaining a girlish spark of unpredictability. Infernal Machines is pulpy adventure, but its women have their own stories to tell and every bit as much agency as its men.

As in any good adventure, things get out of hand and stay that way. Victories prove short-lived. Fisk and Shoe capture Beleth, for example, but other considerations prevent them from killing him immediately, and he may be able to persuade the dvergar to set him free to benefit from his knowledge of engineering and binding demons. Livia and Cornelia capture the ship, which turns out to be highly automated and designed by a man who bears more than a passing resemblance to the chief engineer of the Titanic. But a successful act of piracy creates even more problems than it solves, and even if they can cross the ocean, they still have to find Fisk who could be nearly anywhere on the continent.

And as in any good adventure, when the end comes it is solid and satisfying. Along the way, the worst of the villains have gotten what they deserved until finally the surviving heroes (not all of them, alas) can look back with a mix of joy, relief, and sadness. Infernal Machines is still a Western, though, even if it is full of Rumans:

Gynth came to me. “You will never return, will you?”
“No, hoss,” I said, looking up at the big bastard. “I don’t think we will.”
“I would have you stay,” he said. “[Cousin.]”
“Pard,” I said. “You’ve got a good deal here. This is where you belong.” (p. 359)

There is a sunset, and characters sail into it. With one last surprise at the end.