The episode starts with Tatiana who flies with her Vanship inside the Grand Sream looking for Disith ships as they prepare for a confrontation. Meanwhile, Claus and Lavie vanship two pilots are preparing for a race.

Before qualifying races however Claus and Lavie decide to take a job. They must deliver a message to Duke Madossein by his wife. In addition they also choose to personally hand over a message from her daughter. Madossein Duke is a master of the fleet Anatory, so Claus and Lavie are forced to deliver a message in the middle of a firefight between Anatory and Disith vessels.

In the clash we see Fusilier Moran for the first time in action. The episode ends with Claus and Lavie who climb on the ship the commander Duke Madossein.

Just as Claus and Lavi deliver their message to Duke Madossein, The Guild is hit. Duke Madossein instructs everyone to get to safety, and Claus and Lavi are escorted to their vanship. However, just as they are about to leave, Claus remembers he still has his letter from Holy. Lavi rigs the PA system in order to read it to the Duke and everyone else on board. However, this could be cut short as the first officer send guard to stop Claus and Lavi. But the guards aren't the only ones heading for Claus and Lavi, as Mullin Shetland is touched by the words from the letter.

Sophia arrives at Norkia to parley with Disith commander Nestor Messina and reveals to him a copy of the peace offer lost in the Grand Stream ten years earlier. As a gesture of goodwill, Disith supplies Anatoray with a map of the Grand Stream's air currents and a recording of Exile's acoustic signature. Mullin decides to rejoin the musketeer squad and meets the female Disith musketeer, who introduces herself as Dunya Scheer. They are informed that the capture attempt of battleship Claudia units will occur on the Guild's Covenant Day, when 17-year-old youths pledge their allegiance to the Maestro. Before the Silvana leaves dock, Claus, Lavie, and Alvis say goodbye to Mullin. The formal alliance between Anatoray and Disith is signed at Sophia's coronation as Empress. Claus, Tatiana, Dio, and Lucciola arrive ahead of the Silvana to send congratulations, but Delphine's ship appears from the clouds above and rains down rose petals as a declaration of war. Dio, realizing that he has been found by his sister, panics and flies his vanship erratically. When Alex sees Delphine's ship above the site of the coronation ceremony, he immediately orders that it be destroyed, but his crew refuses to comply for fear of killing Sophia.

Exile enters Disith territory, followed by the Guild and alliance fleets. The alliance fleet loses one-quarter of its ships after Exile continues its indiscriminate attack, but Sophia orders it to continue at all costs to defeat the Guild. In the Grand Stream, Dio pursues Claus's vanship and relives their race at Horizon Cave. However, when he realizes Lucciola is not with him, Dio falls into despair and is thrown off his vanship by a gust of wind. Just as the alliance fleet falters in its attack, the Urbanus leads the remaining ships in protecting the Silvana as she makes a final attack at Delphine's ship. Alex, still a prisoner of Delphine, catches her off-guard and strangles her before breaking her neck. As the Silvana destroys Delphine's ship, Wina hears Alex's final words at her listening post. Claus and Lavie finally cross the Grand Stream into Disith, completing the feat that their fathers could not achieve. There, they find the remaining alliance fleet and bring Alvis to Exile. Claus recites all four Mysteria, to which Alvis responds, and Exile sheds its defensive cocoon to reveal a starship. Inside it, Claus and Lavie find their fathers' vanship and remains. The world they have been living in is revealed to be in the shape of an hourglass, and Exile takes Claus, Lavie, and many others to a new, conflict-free world. Claus and Lavie are reunited with Dunya and Mullin, the latter of whom has recovered from his injuries. They are joined by Alvis, Tatiana, Alister, Holly Mad-thane, and several children.