The Royal Army of Fernest marches on the Plains of Ilys, where the forces of the empire await them. Fernest cannot afford to lose the coming battle.

Luckily for them, they have Olivia, freshly promoted to second lieutenant, who is sent off on a secret mission to assassinate the enemy's commander. With her go Claudia, a serious young knight saddled with the impossible task of keeping Olivia in line, Ashton, a private who has his hands full just staying alive, and a band of green but eager soldiers who worship the ground Olivia walks on.

As the battle rages, their task is to circumvent the fighting and take the imperial commander by surprise... The question is, can the Royal Army hold out long enough for Olivia to finish the job?