On Lampadas, Headmaster Gilbertus Albans runs the Mentat School in an isolated marshland to help students concentrate and avoid outside distractions. Gilbertus worries that he underestimated the lasting power of the Butlerian movement, because Manford Torondo’s antitechnology influence forces Gilbertus to conceal his own complicated history with thinking machines.

During a lecture in the main instruction theater, Gilbertus compares a human cadaver with a deactivated combat mek. By dissecting both side by side, Gilbertus teaches that humans can study the organization and efficiency of machines without being inferior to them. The lesson unsettles some students, especially Alys Carroll, a capable but rigid Butlerian candidate admitted under Gilbertus’s agreement with Manford.

Gilbertus explains that Mentat training is meant to expand memory, calculation, and mental organization until humans can surpass computers. His senior student and assistant, Draigo Roget, helps project the details of the demonstration while the class watches. The students accept the goal, though the scene underscores the dangerous tension between Mentat methods and Butlerian suspicion.

After the lecture, Gilbertus crosses the swamp-bound school complex and returns to an office designed to evoke age, authority, and memories of Erasmus’s former villa on Corrin. Once alone, Gilbertus locks the room, lowers the blinds, opens a hidden mechanism, and reveals Erasmus’s preserved memory core. The chapter confirms that Erasmus secretly helped shape the Mentat curriculum and that Gilbertus’s public identity depends on concealing this forbidden source.

Gilbertus speaks privately with Erasmus, who remains grateful for rescue from Corrin but restless without a body. Erasmus wants mobility and renewed interaction with humans, while Gilbertus insists that the risk is too great because Erasmus is one of the most hated thinking machines in history. Gilbertus briefly lets Erasmus look out over the lake, then prepares for an uneasy trip with Manford Torondo to Salusa Secundus, where they will address the Landsraad and Emperor Salvador Corrino.