As the episode progresses, the brothers' interactions become increasingly intense, and their conversations are laced with a sense of urgency. The actors deliver outstanding performances, bringing depth and nuance to their characters. The chemistry between the brothers is palpable, making it easy to become invested in their individual stories.

"Part Three: Delusion" is where the Galvin family's carefully maintained facade of normalcy shatters completely. The episode follows two parallel and devastating storylines: the psychotic breakdown of 14-year-old following a family death, and the emergence of a dark secret that forces youngest sister Mary Galvin into a desperate and unthinkable situation.

: Overwhelmed by the loss of his son and the unrelenting stress of a chaotic home life, Don Galvin Sr. suffers a debilitating stroke.