Answer:
Chief Bromden considers that the society in which he lives is controlled by The Combine, a sort of millionaire white elite that manages the population at will, especially minorities like him, who is Native American. Thus, he thinks that the pills are an element of domination of this group, that through institutions like the mental hospital and people like Nurse Ratched apply these elements of control to dominate those people who do not want to see progress, alienating them from their own wills and thoughts, and turning them into easily controllable entities.
In chapter 2 of the Lightening Thief, Percy sees 3 old ladies knitting a sock and one cuts a string looking in his direction which symbolizes Percy's lifeline is in danger. The ladies know he is a demigod in danger, and the mist keeps him from knowing this. The mist conceals magic. Later as the book goes on strange events lead to a realization that he is a demigod.
