The 5th Wave by Rick Yancey

speeding bullet.
    It hits the surface with a force one billion times greater than the bomb dropped on
     Hiroshima.
    Bye-bye, New York. Bye, Sydney. Good-bye, California, Washington, Oregon, Alaska,
     British Columbia. So long, Eastern Seaboard.
    Japan, Hong Kong, London, Rome, Rio.
    Nice to know you. Hope you enjoyed your stay!
    The 1st Wave was over in seconds.
    The 2nd Wave lasted a little longer. About a day.
    The 3rd Wave? That took a little longer—twelve weeks. Twelve weeks to kill…well, Dad
     figured 97 percent of those of us unlucky enough to have survived the first two waves.
    Ninety-seven percent of four billion? You do the math.
    That’s when the Alien Empire descended in their flying saucers and started blasting
     away, right? When the peoples of the Earth united under one banner to play David versus
     Goliath. Our tanks against your ray guns. Bring it on!
    We weren’t that lucky.
    And they weren’t that stupid.
    How do you waste nearly four billion people in three months?
    Birds.
    How many birds are there in the world? Wanna guess? A million? A billion? How about
     over three hundred billion? That’s about seventy-five birds for each man, woman, and
     child still alive after the first two waves.
    There are thousands of species of bird on every continent. And birds don’t recognize
     borders. They also crap a lot. They crap five or six times a day. That’s over a trillion
     little missiles raining down each day, every day.
    You couldn’t invent a more efficient delivery system for a virus that has a 97 percent
     kill rate.
    My father thought they must have taken something like Ebola Zaire and genetically
     altered it. Ebola can’t spread through the air. But change a single protein and you
     can make it airborne, like the flu. The virus takes up residence in your lungs. You
     get a bad cough. Fever. Your head starts to hurt. Hurt bad. You start spitting up
     little drops of virus-laden blood. The bug moves into your liver, your kidneys, your
     brain. You’re packing a billion of them now. You’ve become a viral bomb. And when
     you explode, you blast everyone around you with the virus. They call it bleeding out.
     Like rats fleeing a sinking ship, the virus erupts out of every opening. Your mouth,
     your nose, your ears, your ass, even your eyes. You literally cry tears of blood.
    We had different names for it. The Red Death or the Blood Plague. The Pestilence.
     The Red Tsunami. The Fourth Horseman. Whatever you wanted to call it, after three
     months, ninety-seven out of every hundred people were dead.
    That’s a lot of bloody tears.
    Time was flowing in reverse. The 1st Wave knocked us back to the eighteenth century.
     The next two slammed us into the Neolithic.
    We were hunter-gatherers again. Nomads. Bottom of the pyramid.
    But we weren’t ready to give up hope. Not yet.
    There were still enough of us left to fight back.
    We couldn’t take them head-on, but we could fight a guerilla war. We could go all
     asymmetrical on their alien asses. We had enough guns and ammo and even some transport
     that survived the 1st Wave. Our militaries had been decimated, but there were still
     functional units on every continent. There were bunkers and caves and underground
     bases where we could hide for years.
You be America, alien invaders, and we’ll be Vietnam.
    And the Others go,
Yeah, okay, right.
    We thought they had thrown everything at us—or at least the worst, because it was
     hard to imagine anything worse than the Red Death. Those of us who survived the 3rd
     Wave—the ones with a natural immunity to the disease—hunkered down and stocked up
     and waited for the People in Charge to tell us what to do. We knew somebody had to
     be in charge, because occasionally a fighter jet would scream across the sky and we
     heard what sounded like gun battles in the distance and the rumble of troop carriers
     just over the horizon.
    I guess my family was luckier than most. The Fourth Horseman rode off with