Andrew and Emily return to Nashville after a little vacation just before the academic year starts. They encounter radio stations that should be on the air but aren't, anti-technology signage, and a couple of small and violent demonstrations.
It doesn't take long for rolling blackouts and violence to make the city very dangerous. A fascist and nut takes partial control of local National Guard and police units, and imposes martial law. Some of his goons come after Andrew, who barely escapes. He meets up with Emily and they decide they must leave, heading south to where some of the other university faculty and grad students had talked about going.
A new enemy meets Andrew at this refuge - Cholera. This is where they learn about Orange Island being a refuge though the writer didn't use the real name or say what coast it was near, Andrew knew. They head south again.
Chloe gets sick, and they soon lose their car, stealing another. Emily pulls the body from behind the wheel when Andrew hesitates.
They drive south, reaching a town on the Gulf Coast of Alabama where the locals seem happy to take them in for the night but they note the building's been locked from the outside. Emily is again feeling sick. So is Andrew. But they have to leave, slipping out a window in the night.
The locals fire a few shots at them as they flee in a motorboat for "Orange Island" which does host some refugees from the university. Emily, it turns out, is pregnant, not infected. A few days later one of the residents using a shortwave radio contacts someone in the Chicago area. Disease and hunger are rampant there.