The plot revolves around a Union Army regiment and an artillery battery from the American Civil War, which got transported to an alien world.
The 35th Maine Infantry Regiment and the 44th New York Light Artillery Battery travelled to a different world using a ship that emerged from a mysterious electrical storm.
Once the Merki learn of the Tugar's weakening, they seek to take advantage of the Russians, realizing the disastrous effects that would come from an industrialized enemy.
The Merki attack is more successful than the Tugar one and forces the humans to abandon the Russian territory in a scorched earth campaign, but eventually, they win with their use of trains.
This alien, a soldier in his own world, assumes a messianic role among the Bantag and modernizes their society to equal, and even surpass that of the humans.
The reader learns that the people of the Bantag had once been a technologically advanced star-faring race, visiting many different planets and seeding teleportation devices across them.
With the children of the original regiment members reaching adulthood, they face a new threat from across the southern sea, the Kazars, aliens who have an early 20th-century level of technology and who also have a selectively bred slave race of human assassins, called the Shiv.
Keane's leadership under the guidance of his sergeant, Hans Schuder, made them ripe for promotion as they progressed through Fredericksburg, Cold Harbor and Gettysburg.
Analogous to the United States Military Academy at West Point, the 35th is the best that Rus has to offer and provides a place to train new officers for the Army of the Republic.