—Well, he’s not here anymore, and I’m a fast learner. Believe me, when I make threats, there will be nothing empty about them.

—He’s the one who brought me here. You should t…trust his judgment.

—He didn’t trust you! He thought you could help, but he never trusted you. I don’t either. I’ll turn you over to the government the minute this is over.

—Then why keep me here? What mmmm…what makes you think I’ll help if I know you’ll have me locked up afff…terwards?

—Because I trust your sick, twisted ego to always have the better of you. I know that you wanna be the one to solve this. You wanna be the one who saves the world, not because you care, but so you can feel justified, vindicated. I don’t think it matters to you at all whether you spend the rest of your life rotting in a cell.

—That is still him talking.

—I told you I’m a quick study. What do you say we stop wasting each other’s time and you tell me what you’ve been up to these past few days?

—He had me com…pare DNA from the London survivors to genetic material from the alien b…bodies.

—Did you?

—Yes and no. Their ge…genetics is so different, none of my tests will w…work on them. I can’t know how it would recombine with ours, if…it would recombine at all. I’d need live sss…specimens to go any fffurther. It doesn’t matter, I know I won’t find what he was looking for. He thought the survivors—

—He thought they were descendants of aliens who lived here three thousand years ago.

—He thought wrong.

—Are you sure?

—Yes.

—You’re absolutely sure, Alyssa? Why?

—It makes no sense. It’s t…too long ago. Everyone was your ancestor three thou…sand years ago.

—What do you mean?

—People look at fff…family trees the wrong way. They think you start with someone, then you branch down to their ch…children, then their grandchildren, and the tree gets bigger going down. It d…d…doesn’t. It grows upwards.

—How does that have anything to do with the survivors?

—Think of it like this. You have two p…parents. You have four grandparents. You have eight great-grandparents, sixteen great-great-grandparents. That’s about one hundred years ago. Twenty-five years, thirty years p…per generation on average. Two hundred years ago, you’re looking at about two thousand ancestors. Ffffive hundred years ago, that’s…fifty…million.

—How many going back three thousand years?

—Just keep d…doubling every thirty years. You get to a billion very fast. By t…twelve hundred years, you reach a trillion. Three thou…three thousand years ago…It doesn’t matter what the number is. It’s t…too big.

—That makes no sense. There weren’t a trillion people on Earth twelve hundred years ago. There aren’t close to a trillion now!

—That’s because the same p…people appear mmm…many times on your family tree. Your twenty-fifth great-grandfather is also your distant cousin. Mmm…most people will appear hundreds, thousands of times in your ge…genealogy. The farther back in time you go, the fewer people there are on Earth, and the more branches there are in your family tree. Soon, you need…all of them, to fill the b…br…branches.

—I’m not sure I under—

—If you lived on Earth back then, either your line died out and you have nnn….no descendants at all, or you’re an ancestor to everyone alive…t…today. Everyone who lived a couple thousand years ago, and whose line didn’t di…disappear, is your ancestor, and mine, and everyone else’s.

—…

—Dr. Franklin?

—That’s it, isn’t it?

—That is wh…what?

—If aliens roamed the planet three thousand years ago, they couldn’t have just a handful of descendants alive today. They’d either have none—and we know that’s not true, I met one yesterday—or…

—Are you saying…?

—That’s exactly what I’m saying. Or they’d be a distant ancestor to everyone alive. I didn’t survive because I have alien DNA, I’m alive because I’m one of the few people who doesn’t. We’re all aliens, part alien anyway. Every single person on Earth—well, 99.95 percent of them—has alien genetics.

—That’s cr…crazy.

—Thank you, Alyssa. Your services won’t be required anymore. These gentlemen will escort you out and take you…well, we’ll figure that part out soon enough. Goodbye, Alyssa.

PART FIVE

IN THE BLOOD

FILE NO. 1619

INTERVIEW WITH MR. BURNS, OCCUPATION UNKNOWN

Location: New Dynasty Chinese Restaurant, Dupont Circle, Washington, DC

—They came for you, didn’t they?

—What? No hello? No “it’s nice to see you again”?

—They’re here to kill you, not us!

—Fine, then. No hello.

—They made that gas so it would kill anyone who shared genetic material with them. They came here to wipe you out. They probably thought there were only a handful of you. But we all started dying, and they realized everyone on Earth—almost everyone—has alien genes. That’s why they stopped.

—Bingo! I told you you were smart enough! Just enough.

—You lied to us! Everything you told us…Everything you told him, it was all a lie!

—First, I only told him a story. I never said it was the truth. Besides, everything I’ve said is true, more or less. I may have omitted certain parts of the story, but I didn’t lie. A few millennia ago, they sent a dozen of these robots to Earth because they feared an attack from one of their enemies. Nasty people, or so I was told. A couple thousand years went by, no one came, so they went home.

—You said they left Themis behind so we could defend ourselves.

—Yes! They did, for a while. They also left pilots with her. You wouldn’t have been able to use Themis otherwise.

—Because of our anatomy.

—I’m sure they never thought you’d be crazy enough to mutilate your own legs, but there’s a much simpler reason. The controls wouldn’t work for humans. They shouldn’t. Even now, there are only a few people with the right DNA.