On the rooftop of the Mentat School, Gilbertus Albans surveys the apparently calm marsh lake while worrying about the hostility inside the school. His recent classroom debate, in which he argued a pro-machine position as an exercise, has inflamed Butlerian students, who vandalize school buildings and denounce him as a machine sympathizer.

Gilbertus recognizes that the minority of Butlerian students is louder and more intimidating than the moderates, leaving his supporters afraid to defend him. In his darkened office, he consults Erasmus’s hidden memory core. Erasmus warns that if Manford Torondo’s followers discover the core, both Erasmus and Gilbertus will be destroyed, so Gilbertus must appease them, even by lying.

To calm the students, Gilbertus gives a public speech renouncing rationalizations about technology and urging a firm stance against it. The apology partially satisfies Alys Carroll and other angry students, but the crisis deepens when Gilbertus learns that Manford will personally investigate the school.

Manford arrives on Anari Idaho’s shoulders, signaling a confrontational visit. Manford accuses Gilbertus of choosing an undebatable subject and demands to inspect the storehouse of forbidden machine artifacts. In front of Manford and his followers, Gilbertus decides that performance is necessary: he takes a metal rod and smashes robot heads and combat-machine parts, prompting the Butlerians to join enthusiastically in the destruction.

The Butlerians then search the school, invading students’ rooms and finally Gilbertus’s office. As Manford and Anari inspect Gilbertus’s books on Erasmus and the searchers move toward the hidden compartment containing Erasmus’s memory core, Gilbertus fears discovery would mean Erasmus’s destruction, Gilbertus’s execution, and the ruin of the Mentat School.

To stop the search, Gilbertus offers Manford a valuable Mentat projection: the location of a vast abandoned robot outpost or shipyard. Manford accepts the information as proof of loyalty, says he needs the Mentat School intact for his anti-technology campaigns, and promises to publicly affirm the school’s purity. Anari concludes that they will destroy the shipyards.