In “The Pura Principle,” Yunior is approximately 16 and struggling with his older brother Rafa’s cancer. To deal with her son’s sickness, their mother Mami takes to prayer. Yunior says, “She’d never been big on church before, but as soon as we landed on cancer planet she went so over-the-top Jesucristo that I think she would have nailed herself to a cross if she’d had one handy” (92).

Neither Yunior nor Mami can control the rebellious Rafa. Yunior explains, “Not a week out of the hospital, he cracked this illegal Peruvian kid in the face with a hammer and two hours later threw down at the Pathmark because he thought some fool was talking shit about him” (93).

Rafa gets attached to a Dominican girl, Pura, who recently immigrated to America. Amused by how agitated Mami is by Pura, Rafa elopes with the girl. Mami kicks him out of the house. Rafa returns and steals the TV and mattresses. Yunior, now finally stronger than his ailing brother, stops Rafa from stealing money. Rafa swears revenge against Yunior.

When Rafa falls ill again, Pura asks for money and then disappears. Once Rafa is finally home from the hospital, he never mentions Pura again.