Schönkopf and his subordinates from the Rosen Ritter successfully infiltrate Iserlohn Fortress by disguising themselves as Imperial soldiers on the run from the Alliance. He requests an audience with the fortress's commander, saying he wants to relay some vital information acquired during an espionage mission. The commander, Admiral Stockhausen, gives permission, but the captain of the control room guard grows suspicious.

In humanity's distant future, two interstellar states—the monarchic Galactic Empire and the democratic Free Planets Alliance—are embroiled in a never-ending war. The story focuses on the exploits of rivals Reinhard von Müsel and Yang Wen Li as they rise to power and fame in the Galactic Empire and the Free Planets Alliance.

The Free Planets Alliance counters the Galactic Imperial Navy's advance in the Astarte Starzone, still divided into the 2nd, 4th, and 6th Fleets to surround the latter on three sides. The Alliance top brass are certain that their victory is assured, but 2nd Fleet Deputy Staff Officer Commodore Yang predicts the enemy's attack on their divided forces before their encirclement is complete.

The Free Planets Alliance Navy Expeditionary Fleet is fighting a severe supply shortage, and the supply convoy that was sent to save them has been destroyed by Kircheis in a fierce attack. Without their desperately needed supplies, the disheartened Alliance fleet takes a hard hit from the Imperial Navy. As Reinhard's subordinates take out the Alliance fleets one by one, Yang's 13th Fleet is attacked by the Kempff Fleet.

After its defeat at the Battle of Astarte, the Free Planets Alliance Navy returns to the planet Heinessen, the Alliance's capital. A memorial service is being held for the 1,500,000 Alliance soldiers who died in the battle, but according to Rear Admiral Cazerne, it's nothing but a political show put on by National Defense Committee Chairman Trunicht. Yang reluctantly attends the service, but while there, he encounters an old acquaintance he never expected to see

The Free Planets Alliance Navy Expeditionary Fleet encounters a grave shortage of food during its advance into Imperial territory. The 5th Fleet commander, Admiral Bewcock, conveys Yang's proposed escape plan to Supreme Commander Lobos, but Lobos fails to comprehend the situation and won't allow them to flee. Meanwhile, Reinhard has already given orders to Kircheis to strike the Alliance Navy's supply convoy. The Imperial Navy's counterattack has begun!

January 798 UC: A squadron of the Iserlohn Garrison Fleet under the command of Dusty Attenborough conducts a patrol and training mission in the Galactic Empire side of the Iserlohn Corridor, during which it encounters an Imperial patrol fleet under the command of Eihendorf. Hostilities ensue and Attenborough's squadron, largely comprised of trainees, is quickly forced into the defensive. Julian Mintz, one of the trainees, undergoes his first battle as a fighter pilot. The outmatched Attenborough Squadron is on the brink of defeat when it is saved by the entirety of the Iserlohn Garrison Fleet led by Yang Wen-li.

A sudden recall order from the central government of the Free Planets Alliance forces Yang to head for the capital planet Heinessen. Yang assigns the command of the Iserlohn Fortress to Caselnes and von Schönkopf, and departs aboard the cruiser Leda II with minimal personnel, including his second-in-command Frederica and his guard, Machungo.

When the massive Geiersburg Fortress suddenly materializes in the Iserlohn Corridor, Caselnes immediately forwards a request for reinforcements to Heinessen, but now he must prepare for the imminent Imperial attack. Meanwhile, in Heinessen, Frederica is desperately looking for allies to save Yang.

The Imperial fleet relentlessly conducts their assault on the Iserlohn Corridor, one blow after another. As Caselnes is still struggling with organizing an effective resistance, Imperial armored infantry units have landed on Iserlohn, and threaten to establish a bridgehead. Then, former Imperial admiral Merkatz, who defected to the Alliance, asks to be assigned temporary command of the garrison fleet.

An Alliance relief fleet is finally heading to the Iserlohn Corridor, but combat forces on the battlefield are limited, and a wrong move could turn fatal. Should the Iserlohn garrison fleet be unable to break the blockade imposed by Kempff's ships, the reinforcements from Heinessen would be easily destroyed. On the command bridge of Iserlohn, Caselnes and his officers animatedly discuss the countermeasures, but what sounds like the best plan comes from somebody most unexpected.

Until the age of 16, Yang Wen-li spent most of his life on an interplanatary merchant spaceship with his father, who was a trader. After his father's death, Yang entered the Free Planets Fleet Academy to study war history. There, he met Jean, who would become his best friend, and his childhood friend Jessica, a music school student

Sub-lieutenant Greenhill, a woman with an unusually keen memory, is added to the crew of the 13th Fleet along with several other highly well-regarded officers. Captain Schönkopf and some members of his regiment, the Rosen Ritter, board a previously captured Imperial cruiser as part of Yang's plan to infiltrate and capture Iserlohn Fortress, disguising themselves as Imperial soldiers being pursued by the Alliance

A High Council vote determines that the Free Planets Alliance will invade the Galactic Empire. Meanwhile Yang, after having his resignation rejected by Chief Sithole, visits a restaurant with Julian for dinner and runs in to Frederica Greenhill, who was there with her father. The four of them dine together. On the way home afterward, Yang learns that Jessica, the fiancée of his fallen comrade Lapp, has decided to go into politics.

Annerose, Reinhard's older sister, lives in the palace as the kaiser's favorite mistress. As Reinhard and Kircheis make their way to her residence for a visit, they both recall memories of their childhood together. Then Annerose, after greeting them with a smile that hasn't changed since they were young, asks Kircheis to continue looking out for her brother and guide him back toward the right path if he ever goes astray.

A meeting is underway at the Free Planets Alliance Navy Integrated Tactical Operations Center to plan the Alliance's large-scale invasion into Imperial territory. Commodore Falk, an operations staff officer, proposes a plan, but Vice Admirals Bewcock and Yang raise concerns about the dangers of invading with widely separated forces and an excessively long supply line. Meanwhile, Reinhard is concocting a plan to draw the Alliance Navy deep into Imperial territory and destroy them in one fell swoop.

Kircheis suppresses the Castrop Rebellion in only two days of combat, earning a promotion to vice admiral. Meanwhile, Captain Oberstein, having abandoned the commanders at Iserlohn to flee on his own, seeks an audience with Reinhard. Despite Kircheis's misgivings, Reinhard recognizes Obersteins talent as a tactician and takes him on as a subordinate.

Wolfgang Mittermeyer and Oskar von Reuenthal, two renowned admirals under the command of Reinhard von Lohengramm collectively dubbed as the "Twin Pillars", get together and reminisce about their respective pasts, culminating in the event that would lead to the defining moment of their careers: the Klopstock Incident. In March 795 UC, after thirty years of life in exile from Imperial high society, Marquis Wilhelm von Klopstock plotted an assassination of Kaiser Friedrich IV that was to occur during a party organised by Duke Otho von Braunschweig.

Oskar von Reuenthal ran out in a stormy night to seek help from Reinhard von Lohengramm (then Müsel), a rising star in the Imperial Navy that was also known to be disdained by the high nobles. During the meeting with Reinhard and Siegfried Kircheis, Reuenthal convinced Reinhard to save Wolfgang Mittermeyer, in exchange for the absolute loyalties of both of them to Reinhard. Mittermeyer was promptly freed from captivity, and together with Reuenthal, became the first people outside Kircheis to join Reinhard's cause. Back in the present, Reinhard is busy consolidating his authority as supreme commander of the Imperial Navy and prime minister of the Galactic Empire, and to facilitate that he expands the number of commanders under his direct command.

Admiral Kempff, Commander-in-Chief of the Geiersburg Imperial expeditionary force, sends a peremptory declaration of war to the Alliance garrison of Iserlohn. Then Geiersburg's main gun suddenly opens fire with devastating results. On Iserlohn, a confused Caselnes and his officers do not seem to agree on the best strategy to take...

With the return of Yang to the battlefield, the Imperial fleet increasingly loses momentum and is now on the verge of collapse. Admiral Kempff has to come to terms with the fact that his forces are no longer capable of holding the front line, and sends an order of general retreat to all ships. But this is not necessarily an admission of defeat, because he has one last card to play.

Military Police Commander Ulrich Kesler informs Reinhard that Count Alfred von Landsberg and Leopold Schumacher, two former members of the now-dissolved Lippstadt Nobles Coalition that fought against Reinhard during the Civil War, have reportedly infiltrated the Imperial capital of Odin. Unsure of their true intentions, Reinhard first asks Hilde to assure Annerose's safety, then summons Fezzani High Commissioner Boltik. It's June of the 489th year of the Imperial Calendar...

Count Landsberg's family had loyally served the Goldenbaum dynasty for five generations. His ancestors were even involved in the construction of a labyrinthic system of tunnels beneath the Neue Sanssouci Palace, devised to provide a safe escape for the Emperor in case of an emergency. Now this underground maze will prove instrumental in rescuing the Emperor from the usurper.

In a sudden public speech from Heinessen directed to all citizens, Chairman Trunicht announces that epoch-changing events are occurring as a most unexpected defector has arrived seeking protection under the ideals of freedom and democracy in the Alliance. Everyone on Iserlohn is puzzled, but Yang has a hunch that makes him feel aggravated. Then, news from Odin casts an ominous shadow across the entire galaxy.

Reinhard's speech has thrown the whole High Council of the Free Planets Alliance into complete chaos. Public opinion is polarized between disapproval of a folly populist decision, and support for a resolution that honors the core values of the Alliance. For Trunicht, there couldn't be better opportunity to further strengthen his influence over the military. As the future of the galaxy seems to hinge upon a bratty seven-year-old, Julian is appointed with a new assignment that would take him right to the eye of the growing storm.