Alternate fiction is a thankless genre. Not only does an author have to have an intricate knowledge of real-world events, they also have to use logic and imagination to offer a different spin on the world we know.

It’s a near-impossible balance of nonfiction and “what if?” that very few works ever balance well. Author Alan Smale attempts to bridge this cavernous gap between fantasy and reality with his Clash of Eagles trilogy, which imagines a world where the Roman Empire never fell and instead found its way to North America and the Native American inhabitants living there in the year 1218.

In Eagle in Exile, the newly released second act of the trilogy, Smale follows the tale of Gaius Marcellinus, the head of a Roman Legion that lost his troops and now lives among Cahokian society. Attempting to reconcile the differences between his home culture and his adopted people, Marcellinus looks to bring peace, protect multiple warring factions from themselves and figure out his own identity.

The highlight of Eagle in Exile is the world Smale built. It’s familiar, yet foreign. Flying machines and other advanced technology litters the landscape, but the descriptions of the Native American societies and the geographical features all read like they're from an author that drenched himself in research material.

Witnessing the culture of the Native Americans come in contact with the Roman Legions feels natural for that very reason. Smale obviously dove into both Native American and Roman cultures while working on this series, and it shows: landscapes, customs, clothing, conflicts, warfare and other ways of life are effortlessly described here, which allows more “history” to sneak into the alternate history genre than in other works.

The depth of knowledge and detail here is usually reserved for more straight-laced historical fiction books — like Bernard Cornwell’s Saxon Stories — but by infusing those same principles with elements of speculative fiction, Smale winds up carving out something unique for readers.

That very eye for detail and authenticity does sometimes come as a hindrance to the book, though. Coming in at 534 pages, Eagle in Exile tends to meander at points. Scenes have a tendency to linger as Smale attempts to balance Marcellinus’ personal struggles with the world-building going on around him and the larger conflict between the Native and Roman people.

Still, Eagle in Exile has so much working for it that some overlong sections don’t take away from the story’s energy. Warfare, political conflict, family strife — these are all presented in an epic scope where any decision or wrong move can forever change society.

The tense peace between warring tribes and the incoming threat of the Romans play a central role in the conflict, and the political maneuvering by Marcellinus and his crew is portrayed as a slow burn, with decisions and strategies all thoughtfully weighed before being implemented. Smale is too careful a writer to let these societal interactions be handled casually, and while it might turn off readers looking for the narrative to get to the point already, it adds a greater significance to the events of the story.

As the second book in this trilogy, Eagle in Exile (Random House Publishing Group, 2016) offers plenty of new questions, while still wrapping up plenty of the plot points from the first book. It’s a dense read, and one that will probably leave some people confused, especially if they never read the first, but it poses an interesting alternative world for history buffs to gnaw on.