Secrets of San Mercado takes place in a Catholic grammar school in Southern California during the early 1960s, a moment defined by religious authority, cultural restraint, and enforced innocence. The school’s administrators and clergy believe moral order depends on silence, especially regarding sex. The subject is absent from lessons, sermons, and textbooks, treated not as part of life but as a threat to faith and discipline.

The students, however, live in a different reality. Puberty, rumor, confusion, and curiosity press in from all sides, creating a gap between official doctrine and private experience. Without language or guidance, the children attempt to understand their bodies and relationships through guesswork, misinformation, and fear. Authority figures respond with punishment rather than explanation, reinforcing obedience while deepening ignorance.

The novel does not rely on outrage or caricature. Its tone is observant, often darkly comic, and attentive to the ordinary routines of school life. Johnson portrays repression not as cruelty alone, but as a system sustained by good intentions, habit, and institutional inertia. Secrets of San Mercado examines how silence becomes a form of education in itself, and how the absence of honest language leaves lasting marks on belief, intimacy, and self-understanding.