The 17th Unit loses in a competition against the 14th, and their leader chides Nina for relying too much on Layfon. Later that day Machen is going over mail and finds a letter for Layfon postmarked from Glendan, from someone named `Lee-lin`. This surprises her and she winds up keeping the letter. The next day she tries to go to the 17th Unit`s headquarters to return the letter but is too shy to go inside, until Felli arrives, making her run off, dropping the letter. Felli picks it up but does not return the letter immediately.
Felli calls Layfon to her home, as her brother wishes to speak with him, and he helps her cook dinner. After dinner Karian explains about how it seems that Zuellni is for some reason gravitating to areas with many contaminoids, and a probe photo in the direction they are moving shows what Layfon identifies as a male contaminoid. On his way back, he runs into Naruki who asks him to help her out with a matter that concerns the police.
The next day after training Felli leaves the letter under Layfon`s bag, but he runs off and it falls on the floor before he notices, and Nina picks it up. He helps Naruki and the police by helping to apprehend a group of spies who have been trying to steal secrets from the city. Nina finally returns Layfon`s letter to him the next day.