When counting and accounting for the venomous creatures of a region, many people will tell you that you should be looking for the creatures themselves. Look for holes, look for burrows, look for fallen logs suitable for use as nesting sites. This is not bad advice: if followed, it will lead you inevitably to locating the snakes you’re trying to find.

But if you want to find them faster, any good field herpetologist will tell you to ignore the holes, to skip the flat rocks and fallen trees. Instead, they’ll say you should be looking for the signs of rodent activity. By following the prey, you can always locate the predator—and save yourself a great deal of time in the process.

Remember, however, if you follow this advice, that the absence of one half of this equation does not equal the absence of the other. Sometimes, it simply guarantees that you’re about to find a very hungry rattlesnake.

—from the introduction to A Layman’s Survey of the Venomous Snakes of North America, by Dr. Graham Fordham, originally published 2031.

It has been a delight having Anastasia in my class this year. She has a nimble mind and a creative flair that will no doubt serve her well in her future endeavors. I am writing, not to criticize your daughter’s intelligence, but to offer my concerns about its focus.

Anastasia continues to insist, when prompted, that she is a representative of an alien species. It is an unfortunate truth that children can be cruel: her peers delight in triggering this idiosyncratic response, going out of their way to ask her what planet she’s from and whether she will be going back there at the end of the school year. It would be in her best interests to channel this creative energy in a new direction.

If I may be frank, Ms. Miller, while it is against school policy to blame students for their own bullying, Anastasia does not make things easy on herself. I am sincerely concerned about her well-being if she does not find a way to move past this fantasy, and quickly.

Thank you for your time.

—letter home from Mr. Roy Hagar, tenth-grade teacher. Sent November 2012.

Chapter 9

Tucson, Arizona: July 27, 2031

Eleven days pre-invasion

1.

The forest unfolded in a beautiful array of impossible greens and browns, their colors familiar and yet new, like they were coming into prismatic focus. I stood. The air was cleaner than it had ever been, and the taste of it was faintly acidic, like it was eating away the skin at the back of my throat. The sensation wasn’t painful—almost the opposite, a quiet cleansing that would make everything better, if I just allowed it to happen.

“There you are.”

I whirled.