“The Rising,” the second book in Ian Tregillis’ “Alchemy Wars Trilogy,” is a rousing and thrilling wartime romp through an alternate New World. Two hundred and fifty years years have passed since the Dutch combined the magic of alchemy and clockwork to create an unbeatable army of thinking mechanicals called Clakkers.

It is 1926, and the Dutch rule the world with the might of their unstoppable machines. The French, exiled to the New World, resist the Dutch with steady advancements in chemistry and political subterfuge, though clearly the Dutch have the upper hand.

Tregillis alternates between three plotlines. Sargent Hugo Longchamp defends the city Marseilles-in-the-West from an army of Dutch Clakkers. Deposed spymaster Bernice is on the run and attempting to uncover the secrets behind the metageasa, the Clakkers’ mysterious basic programming. Jax, a Clakker freed from the influence of his metageasa, flees across the New World to locate a legendary colony of free Clakkers known as Neverland. All three plotlines move towards a resolution that sets up the concluding volume to this trilogy.

Isaac Asimov’s classic Robot series featured robots who had to follow basic Laws of Robotics, such as robots “may not harm a human being.” Tregillis takes this idea of basic robotic law down a darker path. The metageasa, the secret governing structure that governs Clakkers’ actions, keeps the Clakkers in a state of painful servitude. The Clakkers themselves don’t always understand the orders guiding their behavior. They are slaves to the Dutch, longing for freedom and the exercise of Free Will.

Jax gained his freedom in the first book, “The Mechanical,” but freedom doesn’t provide instant happiness. Now he must confront the complications and metaphysical questions of freedom in a world where most of his kind are still enslaved. Tregillis forces Jax to confront hard questions. What is freedom good for? What should he do with it? What responsibilities to others does freedom require?

Tregillis creates a world of greys, where even the heroes have their darkness. Bernice is ruthless and cunning, but when faced with mechanical captors that ruthlessness is the key to her survival. The foul-mouthed Longchamp lacks social graces and an even temper, but there’s nobody else you’d want in charge when an army of mechanicals surrounds your village and death is certain. Tregillis never loses sight of the fact that war is hell. His characters suffer.

On a sentence to sentence level, Tregillis writes a gripping and entertaining story. His prose shines. Though his book is often dark, it is always a pleasure to read. I have no idea how Tregillis plans to end this trilogy, but if he sustains this level of energy and creativity, it will surely be thrilling and thoughtful.