Deep in the Shadows (Arte Público Press, 2017) is Hipólito Acosta’s unflinching account of his time as an undercover INS agent tasked with apprehending those who smuggle undocumented immigrants across our borders. The memoir covers the major busts of Acosta’s law-enforcement career. Over three decades, Acosta adopts various criminal identities to enter the dens of human traffickers, counterfeiters, drug dealers, and corrupt agents. This is a fascinating look at a hidden world. —René Martínez