Nina realizes her weakness after seeing that she is relying too much on Layfon and the gap of difference between their powers is too wide after losing their current inter-platoon match, which has made her reluctant to do any training with the 17th Platoon. Meanwhile, Layfon is asked by Karian to identify the Dragon Filth Monster that Felli detected in episode 3, which is a Baby-type form, a stronger variant than the ones that invaded Zuellni and agrees to kill it before the city arrives to its location and it reaches the mature stages. At the same time, he volunteers to help Naruki do police work where the latter’s official acceptance into the police force is at stake. During this time, Leerin letter arrives at Zuellni but is mistakenly delivered to Mei, who decides to deliver it to Layfon herself but chickens out and loses the letter which in turn is pick by Felli, who doesn’t give it him despite having the chance many times and decides to just put it under his bag in the locker room which is then found by Nina who decides to deliver to him herself. (thetvdb.com)