The document summarizes two books: The Underdogs by Mariano Azuela about the Mexican Revolution, and The Alienist by Caleb Carr set in 1890s New York City. The Underdogs follows Demetrio Macias, a character who joins the rebel forces but ultimately loses sight of why he's fighting. The Alienist features Dr. Laszlo Kreizler assembling a team to hunt a serial killer with the help of police captain Theodore Roosevelt. Both books provide historical context and detail of their respective settings.