Kishimu Eden no Grimm Reaper III

is the third volume of the Kishimu Eden no Grimm Reaper light novel series, written by Arata Takano and Illustrated by Senmu. It was released under the Dengeki Bunko Imprint in January 2015.

Synopsis
The betrayal of "her" that the boy faces. What is the new truth he should confront?!?

The fierce battle with Iris is over. However, Katsumi Tatsumi Hana Shoujotai had no time to rest, and Katsumi and Yukino had already begun to take action under the special order of Commander Shiramine. The order is to find clues to the person who interfered with the Iris battle-the "traitor." Meanwhile, Bennett, who became a new boss due to the relegation of Ogasawara, who is one of the few understanding people of Katsumi, leads the situation in the worst direction! What is the immoral person that Katsumi and his friends have reached !? Why did "she" betray humanity? The third shocking dark action woven by beautiful final weapons!

(source: Bookwalker JP - Translated)