A new threat appears in the form of Gauna 550, which has ejected countless lesser gauna cores on an intercept trajectory with Sidonia.

Despite being instrumental in their victory, Tsumugi is severely damaged defending Sidonia. Izana, also critically injured, makes a bold decision.

Evicted from his dorm and with nowhere to go, Nagate asks to stay with Izana for a night; Tsumugi has an emotional crisis triggered by a close call.

The Sidonia's new weapon test succeeds, but the crew realizes they can't shut it down; Yuhata sends the garde pilots to investigate the disturbance.

The pilots and Tsumugi repair damage to the Sidonia following the Gravitational Beam Emitter incident; Tsumugi is upset for causing a minor accident.

Izana finds out her 'date' with Nagate was a setup and storms home. Soon after, she is called to be part of a team that will scout out Planet Nine.

The reconnaissance team is attacked by the gauna; Izana and the squad leader manage to escape into the atmosphere of Planet Nine.

Izana and the recon squad leader are pursued by an enormous humanoid gauna. Meanwhile, Tsumugi faces off against the Crimson Hawk Moth.

Nagate rescues Tsumugi but is overpowered by the Crimson Hawk Moth. The situation looks grim as swarms of gauna bear down on the survivors.