Alien Invasion
"They swoop down from the sky in their flying saucers to level New York and Tokyo and London, or they march across the countryside in huge machines that look like mechanical spiders, ray guns blasting away, and always always, humanity sets aside its differences and bands together to defeat the alien horde." (1)
Cassie describes what humans expect an alien invasion to look like. She paints a vivid picture that she contrasts with what really happened. Cassie realizes that the alien invasion that humans always pictured was a fairy tale. There seems to be no way that humans could actually band together and defeat the aliens. As Cassie shows throughout the book, she has a hard enough time trusting individual humans, like the Crucifix Soldier and Evan, much less an entire group of humans.
After the Waves
"I pause inside the last line of trees. A twenty-foot embankment runs down to the southbound lanes, littered with disabled cars, piles of clothing, shredded plastic garbage bags, the burned out hulks of tractor trailers carrying everything from gasoline to milk. There are wrecks everywhere, some no worse than fender benders, some pileups that snake along the interstate for miles, and the morning sunlight sparkles on all the broken glass." (18)
Cassie's words show the reader what the world looks like after the four waves. She depicts a desolate wasteland of things that people left behind, things that were once so valuable and prized, like cars and clothing. Now they sit abandoned everywhere, as people tried to save what was truly precious: their lives.
Travelling
"The day is bright and windless but cold. The sky cloudless. Walking along, bobbing my head up and down, swinging it from side to side, backpack popping against one shoulder blade, the rifle against the other, walking on the outside edge of the median that separates the southbound from the northbound lanes, stopping every few strides to whip around and scan the terrain behind me. An hour. Two. And I've traveled no more than a mile." (28)
Cassie spends a lot of time on her own at the beginning of the book. She is often self-indulgent and scared, afraid that she may be the last human on earth, but also proud that she may be the last one, so that she can show the aliens her best fight. Cassie constantly worries about encountering Others posing as humans and so she isolates herself, willingly avoiding cities and other people in order to ensure that no one will betray her.
The Abandoned Car
"I'm no alien drone designer, but if i were going to make one, I'd make sure that its detection device was sensitive enough to pick up a body's heat signature through a car roof. It never failed: The moment I started to drift off, I imagined all four doors flying open and dozens of hands reaching for me, hands attached to arms attached to whatever they are. And then I'm up, fumbling with my M16, peeking over the backseat, then doing a 360, feeling trapped and more than a little blind behind the fogged up windows." (38)
Cassie worries constantly about the aliens finding her. Isolating herself from people has helped her survive and not be betrayed, but it also leaves her out in the open, the only human for miles. She worries about the drones that fly around, and whether they are sophisticated enough to pick up her heat signature. Cassie knows that she would build that capability into a drone, and wonders what other capabilities and tricks the aliens could have up their sleeves. This gives her insomnia and frequent anxiety as she tries to survive.
