The crisscrossing stories of Mark, a white devout Christian who sells his suburban home to move to Baltimore's inner city, and Nicole, a black mother determined to leave West Baltimore for the suburbs, chronicle how the region became so deeply segregated and why these fault lines persist today. Mark and Nicole personify the enormous disparities in access to safe housing, educational opportunities, and decent jobs. As these characters pack up their lives and change places, journalist Lawrence Lanahan examines what it will take to save our cities and communities: Do we put money into poor, segregated neighborhoods? Or do we move families out into areas with more opportunity? This eye-opening account of how a city creates its black, white, rich, and poor spaces suggests that these problems are not intractable but that they are destined to persist until each of us—despite living in separate worlds—understands that we have something at stake.