A massive fleet led by Oskar von Reuenthal appears in the Iserlohn Corridor. Boasting overwhelming numerical superiority over the defending Alliance forces, the Imperial commander is confident he can crush his opponent in a quick and easy victory. Back on Heinessen, Bewcock warns admirals and MPs that the Empire may be following a less-obvious strategy this time, thus immediate action must be taken to avert the worst. And Yang realizes that his greatest problem of all may not be the approaching enemy ahead, but the supposed friends behind him.

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.

The unexpected stalemate at the Iserlohn Corridor urges the Imperial Headquarters to muster a reinforcement fleet to be immediately sent in support of Reuenthal. Or at least this is what the Imperial crews believe... but as the fleet jumps out from subspace, it becomes clear that Iserlohn is not their destination. Then Mittermeyer, commander of the fleet, announces that they are about to turn the page in the book of history. On Fezzan, people are staring overhead with anxiety as the sky is filled with ships.

After easily putting down a revolt on the planet Shampool, Yang is approached by Commander Baghdash, a Department of Intelligence official. Baghdash informs Yang that the 11th Fleet has joined the coup d'état and is headed his way. While the Yang Fleet and the 11th Fleet engage in the Battle of the Doria Starzone, the coup d'état faction remains steadfast, intervening with military force at a peaceful protest on the capital planet Heinessen.

The battle against the Lippstadt Nobles Coalition has ended, and a victory celebration and audience with the war prisoners is being held at Geiersburg Fortress. The guards forbid Kircheis from carrying his firearm inside, even though he always had permission to keep his weapons in Reinhard's presence before. As the war prisoners face Reinhard one by one, Braunschweig's adjutant, Ansbach, enters with his leader's body in a coffin...

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.

Only a short time has passed since the Alliance's failed invasion of the Empire, and an assassination attempt on Admiral Cubersly, a key figure in the Alliance Navy, further deepens the people's anxiety. On top of that, an accidental explosion the following day takes fourteen young soldiers' lives. Growing discontent has caused revolts to break out on several planets within the Alliance. Bewcock orders Yang to put down these revolts, but before Yang has a chance to deploy, a coup d'état is executed on the capital planet Heinessen.

Kircheis returns to Reinhard after subjugating a frontier starzone. He wastes no time in asking Reinhard if there's truth in the rumor that he knew of the plans for the nuclear attack on Westerland, but let it happen anyway. With the final battle against the coalition of nobles looming before them, the pair's relationship begins to take a turn like none they have experienced before. Meanwhile, the Lippstadt Nobles Coalition, which had barricaded itself in Geiersburg Fortress, prepares to launch all of its forces in the final battle against Reinhard.

With their respective conflicts handily wrapped up, both Yang and Reinhard spend their time in the afterglow counting their regrets.

After defeating Legrange at the Doria Starzone, Yang's fleet heads to the capital planet Heinessen, which has been taken over by the National Salvation Military Council. Though the council's chairman, Greenhill, understands the severity of the situation, he still believes there's no way Yang's fleet can even penetrate Heinessen's gravitational field because of its specialized defense system, Artemis's Necklace. But Yang had a plan to disable Artemis's Necklace...

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.

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.

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...

After easily putting down a revolt on the planet Shampool, Yang is approached by Commander Baghdash, a Department of Intelligence official. Baghdash informs Yang that the 11th Fleet has joined the coup d'état and is headed his way. While the Yang Fleet and the 11th Fleet engage in the Battle of the Doria Starzone, the coup d'état faction remains steadfast, intervening with military force at a peaceful protest on the capital planet Heinessen.

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.

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.

The Free Planets Alliance attempted a large-scale offensive within the Galactic Empire, but with a reversal strategy by Reinhard and the Galactic Imperial Navy, they lost three space fleets. Although the 13th Fleet, led by Yang, maintained 90% strength, the other fleets suffered heavy damage. But Lobos, the commander-in-chief, ordered all remaining forces to gather at the Amritsar Starzone, so Reinhard also ordered all of his forces to head there. Yet another battle between the two armies was about to unfold.

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.

Animosity continues to grow between Reinhard and Lichtenlade, the guardians of the young emperor Erwin, and the pure-blooded noble families with Braunschweig and Littenheim at their center. In the midst of all this, Hilda, the only daughter of Count Mariendorf, visits the Fleet Admiral's Mansion on Odin to meet with Reinhard. When he asks what brought on the sudden visit, she tells him that the Mariendorf household would like to side with Reinhard in the civil war that could break out at any moment.

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.

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.

As the new wind of war seems to reinvigorate the will to fight among the Empire's youth, the military machine moves on to mobilize an attack force of unprecedented proportions. At the Supreme Operations Council, Reinhard reveals his audacious plan, not without sparking bewilderment and skepticism among the assembled admirals. Meanwhile, Heydrich Lang, former chief of the much-feared Department of Social Discipline, tries to find himself a role in the new regime, and a replacement for the Imperial throne is about to be announced.

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.