Returning to the Bee Hive, Niche now knows what's happened to Gauche, why the Marauders are stealing mail, and Reverse's reasons for controlling them, but he's forbidden to reveal the truth. Soon the plot by Reverse to take down the Letter Bees and overthrow the Amberground government begins accelerating. Even worse, the giant insect creatures called Gaichuu are evolving into something new: traitors maybe working within the Hive; plus Niche's sister, who's definitely not friendly to humans, unexpectedly shows up.
