Pedro Mendoza, an elderly grocer, asks Sister Bertrille to read a love letter from a Miami widow. Sister Bertrille urges him to learn to read, but is surprised when he comes to school. Mother Superior decrees that Pedro can't stay, because Bishop Pool won't allocate funds to teach adults. To convince the Bishop, Sister Bertrille promises to have Pedro reading in a month. Backward, but thrilled by his first word, Pedro resolves to read for the Bishop. Sister Bertrille has doubts because Pedro can't tell an F from a P, and is confused by words that sound the same but are spelled differently. Pedro is ready to give up until he hears a sonnet by Elizabeth Barrett Browning and borrows the book from Sister Bertrille. The Bishop is impressed until he finds that Pedro can't read but memorized the poem. To prove he did learn to write, Pedro unrolls a huge banner, Welcome Bish. Pool. To prepare for the Bishop's next visit, Sister Bertrille takes turns with Sisters Sixto and Jacqueline teaching Pedro day and night. Worn out, Pedro thinks it's worth it, until he reads that the widow is getting married to another man. Although bitter that reading brought unhappiness, Pedro discovers the world of books, including the ones in his store. He finds that his partner, Juan, has been robbing him. Moved by Pedro's impassioned speech, the Bishop recommends funds for an adult school. Middle-aged Matilde, with an eye for Pedro, joins the children in school.