The Breakdown

In Chapter 14, Matthew and Rachel use a knife to terrorize Cass. Matthew believes it’s a knife that merely resembles the one used to murder Jane. Rachel knows the truth—that it actually is the murder weapon—but its resemblance is all that matters to create the association in Cass’s mind. The intent is to make her believe that it’s the killer’s knife and that the killer is targeting her and then remove it and convince her that it was never really there. It serves both to induce dread in Cass and to cast doubt on her sanity. This kind of psychological manipulation, when used over an extended period, is called gaslighting, and the knife represents gaslighting in this scene. The novel symbolizes gaslighting via a literal weapon in order to expose and condemn the deliberate and destructive nature of the practice.

Like the knife, Cass’s pills represent the mechanisms of psychological manipulation and control that Matthew and Rachel use to gaslight her. Their scheme relies on her diminished situational awareness and capacity for reasoning. The sedation induced by the pills leaves her feeling muddled at best and often knocks her out to the point that Rachel can move around her house without Cass knowing. This state of sedation gives Cass the sense that she lacks autonomy and control over her life, fueling her shame, guilt, and depression and exacerbating her perception of cognitive decline. As an effective tool in Matthew and Rachel’s scheme, the pills symbolize psychological manipulation. Even before their effectiveness as part of the scheme becomes apparent, Cass must decide whether to take them. She does so without knowing their name or researching what they do or how they work. She takes them at Matthew’s urging and out of desperation. Thus, the pills also symbolize Cass’s powerlessness, her willingness to cede control of her life, and her acceptance that the problem is in her head.