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.

Emperor Friedrich IV of the Galactic Empire has suddenly passed away without naming a successor. Edwin Josef, the son of the late prince and the emperor's only surviving direct descendant, is only five years old. The Braunschweig and Littenheim families, into which the emperor's daughters had married, begin scheming to install their respective daughters as the new empress. Thus begins the battle for the throne between the families who serve as guardians to the emperor's three grandchildren. Reinhard has not sided with any of them yet, so a certain influential power seeks to take advantage of his military strength.

When the Free Planets Alliance Navy conquered Iserlohn Fortress, they took two million Imperial soldiers as war prisoners. And during the Battle of Amritsar, the Galactic Imperial Navy took two million Alliance soldiers as war prisoners. A deal has been reached to exchange all of these prisoners at Iserlohn Fortress. Representing the Alliance at the exchange is Yang, the commander of Iserlohn Fortress. Representing the Empire in place of Reinhard, the one who proposed the exchange, is Kircheis. The two men, who have fought one another with equal resourcefulness in battle, meet face-to-face for the first time at the prisoner exchange ceremony.

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.

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.

The Lippstadt Nobles Coalition devises a plan to lure Reinhard's forces away from the Imperial capital, Odin, and capture the emperor while Imperial defenses are spread thin. While the nobles fight among themselves over who gets to lead this strike, the Mittermeyer Fleet lays a minefield that forces the rebels off-course, and then strikes them from behind. The defeated rebels flee to Rentenberg Fortress. Reinhard sends Reuenthal and Mittermeyer to occupy the fortress, but upon arriving, they are forced into close-quarters combat with the notoriously barbaric High Admiral Ovlesser.

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.

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.

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...

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.

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...

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

The Imperial invasion force returns to the capital Odin, where Reinhard shows very different treatment to the personnel involved in the operation. Meanwhile, dissatisfaction with the new leadership is unexpectedly growing in the heart of one who was once the Empire's most loyal war hero. At Iserlohn Fortress, where peace has temporarily been restored, Yang and Julian have a very frank conversation, and Julian reveals the path he has chosen.

Kesler reports to Reinhard that the palace has been breached during the night. The sun has yet to rise when Reinhard urgently summons his senior admirals and orders them to keep all fleets ready to go into action at any time. Hilde is now beginning to see the byzantine game of power that is being played in cold-blooded cynicism, but in the midst of this, she overhears communication concerning Neue Sanssouci Chief of Security Molt.

Julian is deeply hesitant about his new assignment in Fezzan. Wouldn't he be more helpful to the Alliance's cause by staying at Iserlohn, where the Imperial fleet is more likely to strike, making any available pilot sorely needed in the near future? However, Yang believes that this otherwise unwelcome top-down decision may actually turn out to be crucial to obtaining invaluable insight on where the struggle for power in the galaxy is heading.

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.

On his way to Fezzan, Julian spends several days at Heinessen. Here, he pays a visit to Bewcock to hand over a strictly confidential letter from Yang, which exposes his conjectures about the possible move the Imperial forces are likely to make. As Julian finally reaches Fezzan, he is immediately mesmerized by the freedom and affluence that surrounds him, and starts seriously wondering whether he will ever be apt to his new mission.

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.

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.

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.

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.