Alex announces that they are going to battle against Urbanus. Although she hesitates at first, Sophie announces their mission over the loudspeakers. Meanwhile, Al has come out of her ""coma"" but she has no recollection of what has just happened. Dio refers to her as ""genuine"" but does not elaborate. Later, when Sophia confronts Alex, he tells her she can just leave the ship, but he refuses, reminding him that she is his first officer. Tatiana briefs the vanship pilots on tactics against the Urbanus, and much to Alistia's chagrin, chooses Claus to be her navi.

Lavi and Al prepare water and a lunch for Claus before he takes off. Alex is leading the Urbanus, and three other ships, into the Dragon Fang. While Vincent does anticipate Alex's moves, he doesn't anticipate the other captain's desperate battle response. Despite the Urbanus dealing a crippling blow to the Sylvana, Alex is able to sink two of the Urbanus-class ships.

Al and Lavi are thrown to the ground, and Lavi is knocked unco

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.

After the Urbanus locates the Silvana and ensures its safety, Sophia returns and is surprised that Claus has been taken. Covenant Day arrives, and Dio takes part in the Trial of Agoon to claim inheritance of the Maestro's position by participating in mortal combat against other Principals. Claus, who cannot bear to see Dio fight, worries that he may die. At the same time, the operation to capture Guild Claudia units commences at Horizon Cave. On the Silvana, Lavie finally completes the repairs of her and Claus's vanship. Delphine takes Alvis and Claus to the location of Exile, where they find its defense system has begun attacking Guild ships as well. Exile attacks Delphine's ship but stops when it senses Alvis's presence. Delphine reveals that Exile is a colony ship used by those who first settled on their world. Alex, who has been injected with a truth serum, recites the Mysteria, and Alvis responds to each one. However, he reveals that he has not read the final Mysterion before entrusting it to Sophia. Delphine then receives word that Dio is the Trial's victor.