I pointed to him. “Good question. Thing is, Astrophage is starting to absorb a lot of the sun’s energy. Well, not a lot. Just a tiny percentage. But that means Earth gets a tiny bit less sunlight. And that can cause real problems.”

“So it’ll be a little colder? Like a degree or two?” Abby asked. “What’s the big deal?”

“You guys know about climate change, right? How our CO2 emissions have caused a lot of problems in the environment?”

“My dad says that’s not real,” said Tamora.

“Well, it is,” I said. “Anyway. All the environmental problems we have from climate change? They happened because the world’s average temperature went up one and a half degrees. That’s it. Just one and a half degrees.”

“How much will this Astrophage stuff change Earth’s temperature?” asked Luther.

I stood and paced slowly in front of the class. “We don’t know. But if it breeds like algae does, at about that same speed, climatologists are saying Earth’s temperature could drop ten to fifteen degrees.”

“What’ll happen?” Luther asked.

“It’ll be bad. Very bad. A lot of animals—entire species—will die out because their habitats are too cold. The ocean water will cool down, too, and it might cause an entire food-chain collapse. So even things that could survive the lower temperature will starve to death because the things they eat all die off.”

The kids stared at me, awestruck. Why had their parents not explained this to them? Probably because they didn’t understand it themselves.

Besides, if I had a nickel for every time I wanted to smack a kid’s parents for not teaching them even the most basic things…well…I’d have enough nickels to put in a sock and smack those parents with it.

“Animals are going to die too?!” Abby asked, horrified.

Abby rode horses competitively and spent most of her time at her grandfather’s dairy farm. Human suffering is often an abstract concept to kids. But animal suffering is something else entirely.

“Yes, I’m sorry, but a lot of livestock will die. And it’s worse than that. On land, crops will fail. The food we eat will become scarce. When that happens, the social order often breaks down and—” I stopped myself there. These were kids. Why was I going this far?

“How—” Abby began. I’d never seen her at a loss for words. “How long before this happens?”

“Climatologists think it’ll happen within the next thirty years,” I said.

Just like that, all the kids relaxed.

“Thirty years?” Trang laughed. “That’s forever!”

“It’s not that long…” I said. But to a bunch of twelve- and thirteen-year-olds, thirty years may as well be a million.

“Can I be on Tracy’s team for the rock-sorting assignment?” asked Michael.

Thirty years. I looked out at their little faces. In thirty years they’d all be in their early forties. They would bear the brunt of it all. And it wouldn’t be easy. These kids were going to grow up in an idyllic world and be thrown into an apocalyptic nightmare.

They were the generation that would experience the Sixth Extinction Event.

I felt a cramp in the pit of my stomach. I was looking out at a room full of children. Happy children. And there was a good chance some of them would literally die of starvation.

“I…” I stammered. “I have to go do a thing. Forget the rock assignment.”

“What?” asked Luther.

“Do…study hall. This is study hall for the rest of the hour. Just do homework from other classes. Stay in your seats and work quietly until the bell rings.”

I left the room without another word. I almost collapsed in the hall from the shakes. I went to a nearby drinking fountain and splashed water on my face. Then I took a deep breath, got some self-control back, and jogged to the parking lot.

I drove fast. Way too fast. I ran red lights. I cut people off. I never do any of that, but that day was different. That day was…I don’t even know.

I screeched into the lab parking lot and left my car parked at an odd angle.

Two U.S. Army soldiers were at the doors to the complex. Just as they had been the previous two days while I’d been working there. I stormed past them.

“Should we have stopped him?” I heard one ask the other. I didn’t care what the response was.

I stomped into the observation room. Stratt was there, of course, reading her tablet. She looked up and I caught a glimpse of genuine surprise on her face.

“Dr. Grace? What are you doing here?”

Past her, through the windows, I spotted four people in containment suits working in the lab.

“Who are they?” I said, pointing at the window. “And what are they doing in my lab?”

“Can’t say I like your tone—” she said.

“I don’t care.”

“And it’s not your lab. It’s my lab. Those technicians are collecting the Astrophage.”

“What are you going to do with it?”

She held her tablet under her arm. “Your dream is coming true. I’m dividing up the Astrophage and sending it to thirty different labs around the world. Everything from CERN to a CIA bioweapons facility.”

“The CIA has a biowea—?” I began. “Never mind. I want to do more work on this.”

She shook her head. “You’ve done your part. We thought it was anhydrous life. Turns out it wasn’t. You proved that. And since no alien exploded out of your chest, we can consider the guinea-pig phase over too. So you’re done.”

“No, I’m not done. There’s a lot more to learn.”

“Of course there is,” she said. “And I have thirty labs all eagerly waiting to get started on it.”

I stepped forward. “Leave some Astrophage here. Let me work it some more.”

She stepped forward as well. “No.”

“Why not?!”

“According to your notes, there were one hundred and seventy-four living Astrophage cells in the sample. And you killed one yesterday, so we’re down to a hundred and seventy-three.”

She pointed to her tablet. “Each of these labs—huge, national labs—will get five or six cells each. That’s it. We’re down to that level of scarcity. Those cells are the one hundred and seventy-three most important things on Earth right now. Our analysis of them will determine if humanity survives.”