“The Sisters” opens with the narrator, a young unnamed boy, reflecting on the impending death of his friend Father Flynn who is a priest at St. Catherine’s Church. The narrator informs the reader that Father Flynn is an old man who has just had his third stroke which left him paralyzed. Knowing that after three strokes the paralyzed priest has little time left, the boy makes a habit of walking past Father Flynn’s house every night. He studies Father Flynn’s window each time he visits the house because he is looking for the light of the traditional two candles that would inform the boy, and anybody else who happened to walk by, of Father Flynn’s death. According to custom, two candles must be placed at the head of a corpse.  

The narrator softly repeats the word “paralysis” to himself every time he passes Father Flynn’s little house on Great Britain Street. He remarks to himself that paralysis is an odd word and that to say it or think it makes him feel strange. He compares the confusion he feels when he hears the word paralysis to the confusion he feels when he hears the word gnomon in the Euclid and the word simony in the Catechism. The narrator’s confusion then transitions into fear as he feels the word paralysis take on a malevolent presence. The narrator is indeed frightened but he is also simultaneously drawn to the room where the paralyzed man lies and he has a morbid longing to witness the effects of Father Flynn’s third stroke. 

An indeterminate amount of time passes. One night, at his aunt and uncle’s house, the boy arrives at supper to find his uncle and Old Cotter, a family friend, sitting before the fire. The narrator’s uncle and Old Cotter are in the middle of discussing an unidentified person. The narrator overhears Old Cotter express his opinions on the man that they are discussing who Old Cotter describes as a “queer,” “uncanny” type of person. Old Cotter goes on to say that the unnamed man is one of those “peculiar cases” but he does not elaborate his point any further. The narrator is irritated by Old Cotter’s presence and refers to him in his mind as a “tiresome old fool.” The narrator used to find Old Cotter interesting when he was younger but has since lost interest in him and his stories.