With MEDUSA finally launched, Crome begins guiding London east towards the Anti-Traction League's base behind the Shield Wall of Batmunkh Gompa in order to destroy their defenses and devour all of their settlements. After Valentine returns, Katherine learns that MEDUSA was originally found by Hester's mother Pandora, and that he had killed her to steal it for London. He also admits that Katherine was likely Hester's half sister. Disillusioned, and horrified by the destructive power of the weapon, Katherine and Bevis conspire to plant a bomb to destroy MEDUSA, but are caught in their attempt.