A2 arrives at the base of the tower and finds Devola, who has been infected with the virus that previously afflicted Popola. After A2 assures Devola of how important she and her sister are, she ends her suffering, thereby losing hope for a cure for the other androids. When 9S enters the tower, he finds himself inside its vast, labyrinthine interior, characterized by a gothic, Escher-like architecture. He is greeted by the voices of the Red Girls, which transition without explanation into the voice of an old man.
The Red Girls confront 9S with a chamber full of hostile clones of 2B, all bearing a malicious expression. 9S recognizes the differences in their movements and faces and can distinguish them from the original 2B. He defeats the clones, but the last one self-destructs, leaving him without an arm and infecting him with the virus.
Meanwhile, A2 enters a massive library containing all of humanity's knowledge. When a glowing book repels her with an electric barrier, she asks Pod to unlock her hacking abilities. As she delves into the digital world previously visited by 9S, she discovers that humanity has been wiped out and that the YoRHa project was designed as a sacrifice. Pod then infects the Red Girls with a virus and instructs A2 to buy time for the virus to take effect.
Both A2 and 9S are attacked by gigantic machine lifeforms, now spoken for by the old man, who are engaged in an internal conflict. The virus spreads through the machine network, causing them to destroy each other. They hurl themselves into the tower's massive cannon, which is meant to destroy the human servers on the moon and erase all remnants of humanity—a step the machine lifeforms deem necessary for their evolution.
With the machine lifeforms deactivated, only A2 and 9S remain. A2 is determined to prevent the destruction of the moon server, while 9S, now using one of 2B's arms, is resolved to avenge 2B by killing A2. Infected and with no regard for his own survival, 9S engages A2 in battle, setting the stage for the impending confrontation.
This article was originally published in German. It was translated with technical support and editorially reviewed before publication.