The Empire is a powerful military nation on a continent that looks much like early 20th century Europe. But in this world, magic is real. The Empire is involved in a war against the Entente Alliance, and fighting a poorly executed delaying action in the northern theater. Second Lieutenant Tanya Degurechaff leads a small platoon of mages. But there's something unusual about this lieutenant... she's only nine years old!

After her stunning success with her first mission, Tanya is assigned to test a new piece of technology: a highly unstable prototype calculation jewel. This jewel offers her unparalleled power, but just using it risks her life. Tanya is determined to get out of this project and on to someplace easier and safer (like the front lines of the war), but Being X has other ideas...

The war with the Entente Alliance is done, and it's back to the Rhine for Tanya and her forces. The Republic troops are highly trained, well-equipped, and stronger than any she's faced before. And in a distant hospital, a former Kingdom officer wakes up, with a mission from God imprinted on his mind...

Tanya just barely manages to restrain herself from disobeying her superior officers and attacking the Republic remanents. But the Republic forces have escaped overseas, and vowed to fight to the bitter end. The Empire has been victorious, but in its victory it has terrified the rest of the world and spurred them to action. Is true victory possible at all?