Monteserrat Fontes writes First Confession about two young cousins who live in a Mexican border town. Born as liminal figures in their culture, Andrea and Victor both are born of mixed racial ancestry, wealth in a poverty stricken town, and irreverence among a religious people. Neither of the children fit in very well, but they're trouble makers, so they prefer it that way. While preparing for their first communion, the kids look for adventures. After witnessing a shop owner get paid for elicit sexual favors, they decide to locate and steal her secret stash of money. The kids end up destroying this woman's reputation and getting her murdered. Grown up, Victor is overcome with guilt for the entire affair and commits suicide, eager just to escape the derision of the townsfolk. This drives Andrea to reconsider how she views her relationship to Victor as well as her responsibility in his and the woman's deaths.
Andrea and Victor are already outcasts when the novel begins. They do not belong to same social class, race, or even attitude as their peers in the village. To them, life is seemingly boring because they witness but do not share the hardships of the rest of the town; instead, to the kids, everyone seems overly serious and rude. They want to have fun, but they have absolutely no idea of the privilege which their parents have given them which allows them to be in this position of boredom.
As such a deliberately contrary child, Andrea learned that people could be hateful. She treated them poorly and in return they treated her poorly, reinforcing her private conclusion that people were hateful. As an adult, she understands how inappropriate her grudges had been considering the pretty extreme problems which everyone around her in the town had been dealing with and continue to struggle through. Coupled with Victor's suicide, this realization teaches Andrea of her own potential for evil. She recognizes the significance of her decisions by paying for her role in the prostitute's death with social shame.
