The dybbuk is one of the most prominent motifs of the novel, representing the theme of Trauma and Familial Repression. The dybbuk is first introduced in the Prologue through a saying taken from the Fletcher family mythology: “a dybbuk in the works” (27). Zelig and Carl initially used the phrase to explain malfunctioning technology at the factory, which is transposed against the people of their family to downplay psychological scars. It is ultimately used to undermine the impact that Carl’s kidnapping has on him. Whenever Carl experiences a depressive episode related to post-traumatic stress disorder, Phyllis explains it away to her grandchildren as a dybbuk possessing Carl. This teaches them to make a distinction between Carl’s core self and his behavior at any given time.

Later on, the characters respond to manifestations of their subconscious desires by calling them dybbuks. Nathan, for instance, calls Phyllis a dybbuk after he starts seeing her in his dreams. Her appearances remind him of his own mortality and his fear of death. Likewise, Marjorie identifies Phyllis as a dybbuk when Ruth visits her near the end of the novel. While Marjorie is later revealed to be under the influence of drugs during this encounter, her identification of the dybbuk points to the unresolved relationship between her and Phyllis.