| This article is incomplete.|
Please feel free to edit this article to add missing information and complete it.
Specifically, it needs the Japanese release date.
Den of Treachery (詭謀の栖 Kibō no Su?) is the 1st chapter of the 7th volume and the 21st chapter overall of the Attack on Titan: Before the Fall manga, written by Ryō Suzukaze and illustrated by Satoshi Shiki.
The rest of the Titan cult gets rounded up and Gloria allows new recruit Xavi Inocencio to interrogate the leader. Later on, Gloria calls in Xavi and requests he act as her proxy during a trip to the Industrial City. In the city, Jorge Pikale returns and notifies Kuklo and Cardina that he is arranged for a test of the new device outside the walls. As Jorge, Kuklo and Cardina travel through the forest the following day, they pass by the carriage carrying Xavi.
In the dark of night, a group of Titan cultists are fleeing from a small band of Military Policemen. The cultists manage to lose the police until they are cornered by Xavi, whose sword is drawn. Xavi taunts the cultists, who draw knives and charge at Xavi. Xavi quickly kills the cultists, and the leader of the Titan Cult draws a gun of Xavi, who tackles him as he fires. Other Military Policemen arrive quickly at the scene, where an unharmed Xavi has caught the leader of the cultists. Xavi thinks to himself about how foolish the policemen are for running towards the sound of gunfire without a second thought. Captain Gloria Bernhart arrives and congratulates Xavi, ordering for the leader to be brought to interrogation. Xavi requests to interrogate the cult leader himself, and Gloria grants him this permission.
The next day at the washing stations, Xavi washes blood off his hands. Other Military Policemen arrive, taunting him and threatening to beat him into submission for showing off. Shortly afterward, a battered Xavi leaves the area with the policemen knocked out behind him. Gloria greets him and congratulates him again for his success. She orders him to head to her office to tell her in person what the cult leader said.
In Captain Bernhart's office, Xavi asks if he is to be punished for assaulting the other policemen. Gloria claims she knows nothing of the situation. She informs Xavi of the declining state of the Military Police, stating that she and other officers have recognized the great potential and ambition Xavi possesses. Xavi then gives his report: the cult leader said that no other cultists were left in Shiganshina District, and Xavi is confident that the Titan Cult has been wiped out. Xavi denies any sense of vengeance for his father, saying the mission was simply his duty as an MP.
Gloria then gives Xavi her own assignment. She plans to send him to the Industrial City as her proxy to request equipment since she and Captain Jentsch Dafner do not get along since her uncle Bauduin Bernhart and Dafner are rivals for the position of Commander of the Military Police. She says, however, that this equipment request is a cover for Xavi's true mission, which she reveals to him.
In the Industrial City, carriages of weapons and armor are brought in for repairs. Xenophon laments the arrival, since production will inevitably be slowed by the repair orders. Xenophon decides that this may be a good opportunity for Sharle to test her new skills as a worker.
As Kuklo and Cardina begin to unload the shipments, they are greeted by Jorge Pikale, returning from an absence of three and a half months. They head inside to catch up, and Jorge informs them of the extermination of the Titan Cult. With the Military Police Brigade's activity declining, they will now be able to test the device. Xenophon presents another prototype, lamenting that despite it being the peak of his ingenuity it is still incomplete. Kuklo assures him that it does not matter if it is incomplete, since practice will point out the flaws that need improvement. Jorge warns them that it will be a live test against a Titan, but Kuklo is unfazed. They make plans to leave for Shiganshina the next morning, with a farewell banquet to be held that afternoon.
Outside, a mysterious man creeps out from beneath one of the shipment carriages, strolling into the Industrial City disguised as a common worker.
In a Military Police carriage, Xavi is being escorted by Matteus, a superior who has been assigned to supervise Xavi's mission. Xavi wonders about Sharle's location, recalling Rixner's idea to send a spy into the Industrial City to locate Sharle. Xavi smirks to himself, confident in his ability to use Captain Bernhart to suit his own needs. Matteus keeps a close eye on Xavi.
Kuklo and Cardina take a carriage out of the Industrial City, passing Xavi's carriage.