Winterbough has left his homeland, the Vale of Elfhame, to join the Imperial & Royal Army of Faerie. He has a somewhat rough time of it in training camp, but he is unexpectedly summoned to the presence of Prince Roland Sartoriusson, the Marshal of Faerie and commander of the I&RA (also the younger brother of King Adler the Prudent).
The Marshal gives Winterbough a curious assignment; he is to be the soldier-servant for an aristocratic officer, Lt. Sir Jasper Chitterleigh, a squirrel mel. Chitterleigh is a good-hearted, if somewhat scatter-brained and not terribly responsible aide-de-camp to the Court. Winterbough arrives at Chitterleigh's bungalow, to find that his predecessor as Chitterleigh's soldier-servant has left the place in total chaos, which he must untangle.
In the course of straightening out Chitterleigh's tangled affairs, Winterbough encounters Eudora Eichelgruber, a charming squirrel-femme from an impoverished family; she teaches music and dance to members of the Court. At the same time Lt. Chitterleigh encounters Miss Eichelgruber, Winterbough encounters Eichelgruber's maid, the mouse-femme Meadow Grainmaster. The small rodent soon proves to be quite a bit more than she appears at first blush.
Lt. Chitterleigh gets tangled up in the schemes of his father, Lord Twelveoaks. His Lordship is one of the King's Ministers, and he has a scheme for trying to arrest the decline in fertility of the Fair Folk that involves intermarriage with the "Lowfolk" (i.e., not Elves). An attempt to put this plan into action at a party fails rather spectacularly, and is in part the reason for Twelveoaks' fall from power.
Winterbough starts to get some hints that he may not come from quite as humble a background as he thought; it seems some furs in power, such as the commander of the Household Cavalry, Col. Briarrose, strangely knew Winterbough's now-deceased mother, Stella Winterbough. There are also some hints of other plots that are afoot, in part because of repeated meetings with a sinister wolf.
In the meantime, Winterbough is doing something quite unusual; he is studying to become an I&RA magick-user; if successful, he would be the first "squaddie" (enlisted fur) to become an Eye-Badge wearer in many years. He uses the knowledge he gains to save a fur from being unjustly convicted in a court-martial.
At a ceremony marking the seasonal transfer of the Court from Albric Tor, the summer capital, to Persoc Tor, the winter capital, a lupine assassin attempts to kill both Marshal Roland and Crown Prince Gawain, using stranglewort-laced arrows. Both Lt. Chitterleigh and Private Winterbough foil the plot, at the cost of both of them suffering serious cases of stranglewort poisoning; Winterbough saves Chitterleigh's life by freezing the poison, and sucking it out of the wound.
Chitterleigh is promoted to Captain, and ends up marrying Eudora Eichelgruber. Winterbough is promoted to Corporal. That, however, is not his only reward. He is made a Blood Seal Bearer, part of a select group that fursonally serves Marshal Roland. Winterbough is sent to the eastern border of the Empire, because Marshal Roland believes that that border is under threat by the Grand Duchy of the Grey Horde, a lupine realm.
Winterbough, upon arriving in the tiny hamlet of Mossford, encounters not only the locals, but the members of Thorn Platoon, a group of "Auld Sweats" whose discipline has suffered somewhat from a skiving commanding officer, an absconding sergeant, and a mysterious, perhaps non-existent, junior officer. One of the locals that Winterbough encounters is a very old, very powerful and slightly mad fox, an elf that calls himself Estvan Silverbrush. Silverbrush takes a liking to Winterbough, and takes it upon himself to be the latter's mentor.
In the meantime, however, events move forward. The neighboring realm of The United Cities, a state run by a confederation of squirrels and chipmunks, is under increasing threat from The Grey Horde. Winterbough must whip Thorn Platoon into shape to meet the threat. At length, he is finally ordered to infiltrate The United Cities after that realm is invaded and occupied by The Grey Horde. To assist him, a large canine squaddie that is an expert in the use of the sling-staff accompanies him.
As it turns out, there is a second Blood Seal Bearer on the job -- Meadow Grainmaster. Together, the three furs neutralize a group of wolves, and reach Sainted Oaks, the principal city of The United Cities. There, they break into a prison and release not only that realm's main leader, but a fur that had been part of the Empire's overrun embassy -- Sir Jasper Chitterleigh. The trio manage to bring back the duo through a running fight in the woods leading back to the border, and from there, the fight is on with the wolves.
Thorn Platoon's parent regiment is fighting a short distance away, at Flourford, but the platoon itself at Mossford is largely on its own, and a multi-day fight breaks out. The climax of the fight is an encounter between Winterbough and The Great Wolf, who commands an elite force of mounted cavalry. Winterbough, by using magicks, defeats not only The Great Wolf, but causes the destruction of the cavalry force, by making it plunge through the ice. This particular encounter would have significant effects on Winterbough's future reputation.
Just at the point where the remnants of Thorn Platoon are about to be overrun, relief comes, and the Grey Horde is put to flight. Winterbough, Grainmaster and Chitterleigh are evacuated to what is left of Flourford. There, they encounter Chitterleigh's father, Twelveoaks, and figure out that it is he, Twelveoaks, that turned traitor in wrath over his demotion. The squirrel is arrested by both Winterbough and Grainmaster.
New of the battle has reached GHQ, and Chitterleigh is ordered back to Persoc Tor at all speed, for if he dies before he reaches the capital, he cannot receive the Valour Medal, the I&RA's highest award. As it is, they make it just in time. Chitterleigh dies in the arms of his beloved mate.
Winterbough himself receives the Valour Medal for his role in Flourford-Mossford, and some of the loose ends regarding Thorn Platoon are resolved...though one not until the very end of the story, when Winterbough hears a surprising fact from King Adler himself.