Silo
Warning: There are spoilers ahead for the Silo season 2 finale.
Earlier in the season, Bernard blackmails Walker into being a spy for him on the Mechanical level.
Due to the loud noises from the generator, Mechanical workers had to yell to communicate.
Walker taught the system of hand signals to the younger generation as well.
The series delves into the complex social order within the silo and the mysteries surrounding their subterranean existence.
Image via Apple TV+
