It is a day of competition between two other military arts units and Nina has declared that the 17th Unit has a rest day, but everyone is encouraged to watch, which only Nina and Harley do. Felli is nowhere to be found, Sharnid has a date, and Layfon has been invited by the three girls. Only Machen shows up, and it turns into something like a date. The city suddenly stops moving, jolting everyone, as the city`s legs have gotten stuck in a pit filled with larval contaminoids.
The military arts students are deployed to defend the city as the larvae enter a breach. Layfon tries to dissuade Nina from participating but she will have none of it. Layfon himself is troubled but eventually decides to join the battle as he realises that everyone he has come to care about in Zuellni could die. Nina is nearly killed at the front lines as her attacks are not so effective against the larvae when Layfon arrives and manages to very easily destroy many of the larvae. He realises that there must be a dormant mother somewhere underneath which will be trouble if it wakes up, so he goes outside into the toxic atmosphere unprotected. He manages to find and destroy the mother with Felli`s guidance and returns to the interior of the city just as he collapses.