I wish there were math for that. To figure it out. Or an abandonment supercollider, where you could take all the leaving particles and throw them in there and understand how they work, why they work. Maybe abandonment is necessary for certain species to thrive. Such as astronauts. Being alone is a big part of the job. You can’t relocate your whole family to the ISS just because you have a job there. And then, of course, that job site is four hundred kilometers away from most of the human species.

Dad always said that our greatest hardships end up giving birth to our biggest strengths. Maybe everyone leaving me is a sim. Getting me ready for being alone in those fighter jets, alone outside the ISS in my space suit, fixing a broken part. Maybe it’s a good thing.

But.

If I don’t die on a mission, if I die when I’m old, then I don’t think there is any way to prepare for that. I will be all alone because everybody leaves, they all leave, and it will take ages for anyone to find me, to know I’m dead. And the paramedics will open the door of my house, my orphan house, and the smell will be horrific.

This loneliness, a deep pit. A grave.

It’s the thing that will kill me next.

I have to work this problem. And this means keeping my sister alive. Because I want to be an old lady with her. I think that would be fun.

By Friday of our second week at school, I decide it’s time to stop being afraid of her pushing me away. Better to have her mad at me than be dead from an overdose. I will confront her. If this doesn’t work, I will have no choice but to enlist the help of others.

The bell rings at the end of the day, and I find her waiting for me in her usual spot, sitting on the low wall in front of the brick-and-ivy building. She’s talking to that vampire-looking boy, and when he sees me, he squeezes Nah’s shoulder, then walks off.

“He’s the guy from your math class, right?” I say.

“Yep.”

“What’s his name?”

“Drew.”

“Like, Andrew or—”

“Just Drew, Mae.”

She tilts her head up, looks at the sky. Blue, not a cloud. My favorite kind of day because it means great visibility for stargazing once it’s dark.

“It’s good. To make a friend,” I say. “Maybe he can come over sometime and—”

“Yeah, no. We’re not friends. Just friendly.”