This is one of the vignettes from the longer novel by Sandra Cisneros entitled The House of Mango Street. In it, the author explores the reality of life as an immigrant through the lives of many different Latinos who have entered America. Thinking about this particular vignette, therefore, we can say that the main message focuses on the reality of life for the illegal immigrant, the "wetback" or "mojado" referred to in the tale. Note how Geraldo by necessity must remain as anonymous as possible - he gives "no last name." Life gives him little opportunity to connect with other people - Marin and Geraldo meet only by chance one night, and Geraldo only gives her limited information about his life and what he does. Even the little information that he divulges is forgotten by Marin, suggesting how cagey he was about his own personal life.
However, note too, how the tragedy of Geraldo's death and anonymity is also spread out to include the tragedy of immigrants in general. Immigrants like Geraldo are shown to live in terror of deportation, which builds a wall preventing communication iwth others and also from developing friendships. And of course, the tragedy extends to Geraldo's family, who will never know his fate:
The ones he left behind are far away, will wonder, shrug, remember. Geraldo - he went north... we never heard from him again.
Thus in this vignette Cisneros creates a pitiful picture of life as an illegal immigrant, pointing towards the harsh reality of their lives - a harshness that operates on so many different levels.