Alex kills the pilot of the star-shaped ship and takes Alvis on board the Sylvana, leaving Lavi and Claus behind. Claus repairs the vanship and obtains extra fuel from the downed ship nearby. He and Lavi then follow the trail of the Sylvana, for Al's sake. Al wakes up on the ship and meets Sophia. When the vanship catches up to the Sylvana, Alex allows the ship to fire upon them, but they are able to avoid getting hit and they ""crash-land"" on the Sylvana. They encounter mechanics in the hanger, and Claus is beaten up by one of them for fun. However, Tatiana and Alistia show up and Tatiana grudgingly asks for Claus' name. Lavi helps Claus up to the bridge, where they meet up with Alex again. At that point, Claus' injuries get the better of him, and he falls unconscious.

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

In the Emperor's absence, Sophia orders the Urbanus to stop General Vitellius from attacking Disith in compliance with a ceasefire. The arrival of Duke Mad-thane's fleet forces Disith to withdraw. The following day, a vanship courier arrives with a message from Walker, who invites the Silvana to Horizon Cave for repairs and resupply. Lescius reveals himself as a member of the purged House Dagobert and entrusts Alex with the third Mysterion. Prime Minister Marius, a member of the purged House Bassianus, also sent the final Mysterion to Alex before his death. The Silvana finally arrives at Horizon Cave, currently used as a training base for an assault against the Guild. Although the Guild suspects of a rebellion, Delphine decides not to take immediate action. At the base, Claus meets Mikhail Wednesday, elder brother to the late Ralph Wednesday from whom Claus took over the duty of delivering Alvis. Claus and Lavie are also reunited with fellow vanship pilots from Norkia after Duke Mad-thane, who was inspired by Claus's and Lavie's actions at Minagith, called for all pilots to fly as fighter support.

A portion of the Guild fortress breaks apart and falls away from the Grand Stream into Anatoray. Claus escapes in the vanship that was brought with them to the Guild stronghold and takes Alvis and Dio to Norkia. Dio is then left in the care of the Mad-thane residence, which has been converted into a makeshift hospital. Claus takes Alvis back to his wrecked house, where they stay overnight. The combined Anatoray and Disith alliance fleet launches a surprise attack on the Guild fleet and, helped by the vanship squadrons, emerges victorious. It continues to pursue the withdrawing Guild ships into the Grand Stream. When Claus and Alvis are finally able to contact Lavie and the Silvana with Lucciola's communicator, they are told to make a rendezvous at the Dragon's Fangs.