Empress Asseylum Vers Allusia declares a cease-fire and, with Slaine Troyard's resolve seemingly shaken, a rift surfaces between the Orbital Knights. Inaho Kaizuka and Slaine Troyard finally settle their differences on the battlefield.
The episode begins right where the last episode left off, at Princess Asseylum's proclamation of becoming Empress, and taking Count Klancain as her husband. The reactions of the remaining Orbital Knights are shown, with them believing that Asseylum was going to marry Slaine. For the first time in the series the opening is not shown in the near beginning of the episode. The fighting continues with the UFE questioning why. Slaine then talks with Lemrina, and she mentions how she is always going to be there for Slaine. Slaine mentions that he as seen many things out there in battle. Slaine orders an evacuation of the Moon Base, telling the Vers soldiers to surrender, and telling Lemrina to get on a evacuation shuttle. Lemrina is forced to watch from afar as Slaine blows the Moon base all while he is standing alone in the command room.
Harklight turns around from evacuating and re-joins the battle, bringing with him the Stygis Squad. Slaine orders Harklight to surrender, but Harklight say, "I have already made my peace with death. Please allow me this one selfish act". Motivated by seeing his soldiers fight again, Slaine joins the fight, and faces off with Inaho Kaizuka for the final battle.
With the background music of "Keep on Keeping On", the final battle commences. Earning the first advantage Inaho manages to snare Slaine in his grapple hooks. Opening up communication channels, Inaho asks Slaine to surrender. Slaine mocks him by saying, "did you come all the way up here to just ask me that?". Inaho says that he has a different objective. Slaine then manages to escape Inaho's grasp, but his Tharsis monitors are damaged. Turning them off Slaine says that he doesn't have a future anymore.
A brief battle between the Deucalion and the Vers forces is shown.
Returning to the main battle, both Inaho, and Slaine have turned to swords, with Inaho having multiple back-ups. Inaho manages to slice up Slaines' sword, and Slaine is defeated.
Harklight, the Stygis Squadron, and Count Barouhcruz are seen leaving the battlefield. Barouhcruz mentions how the Terrans are strong, and Harklight mentions they were born on the same planet as Slaine. They all then turn around, and charge head on at the Deucalion, and are presumed killed.
Slaine and Inaho then fall towards Earth, as Inaho grabbed onto Slaine, and acts as a drag chute, as they fall. As they fall the same two children from the ending of Princess of VERS are shown, again mentioning the shooting star. Unlike the first time the older sister looks worried.
Slaine is shown on a beach battered, with the two Kats in the background destroyed in the water. As Slaine is crawling inland, Inaho points his gun at Slaine. Sitting up Slaine points his finger towards his forehead similar to Count Saazbaum in Childhood's End. A helicopter is heard.
After an unmentioned time in the future, it looks like peace is once again achieved. To strengthen the bond between the two planets, an Aldnoah Reactor is created to give Aldnoah activation power to everyone on the planet. And the Vers Empire would be the ones to export the Aldnoah power to Earth. Various scenes are shown depicting the lives of the characters after the war. It is mentioned that Slaine was killed, and that he was the one who planned Asseylum's assassination. (This is a scapegoat on Slaine). Empress Asseylum, wishing for peace awakens the Reactor.
Inaho is shown visiting Slaine in prison. Inaho is now wearing an eye patch over his now removed artificial left eye. Slaine asks why he saved him. Inaho answers that he did it because the Princess asked him a favor, to save Slaine. Slaine becoming emotional cries. Inaho leaves the prison with his sister Yuki driving the jeep away. Asseylum is seen talking with Klancain on a battleship, saying that her time spent with Inaho on Earth are "lovely memories."
- Heavenly Blue (ED)
- The Brother and his Sister that appeared in the very first episode are seen again. Once more, he points out to his sister the shooting star in then sky. Unlike before, it is not debris from a Landing Castle but the Tharsis holding onto Inaho's KG-6 Sleipnir. However, beneath the falling Kataphraktoi is the abandoned burnt out Landing Castle.
- Asseylum explains why the sky is blue to Klancain, as she was taught by her "Terran friend", referencing her conversation with Inaho in the sixth episode. This time, the Terran friend in question is Inaho and she gives the correct explanation, Rayleigh scattering.
- "Inherit the Stars" is a reference to James P. Hogan's 1977 science fiction novel of the same name, where a substantial prehistory of the Solar System is given, and a series of wars are fought between humans from different planets.