Venus’s atmosphere is ninety times Earth’s pressure and almost entirely carbon dioxide. Its spectroscopy signature of CO⁠₂ would be overwhelmingly strong. Mercury had no carbon dioxide at all, so the nearest competitor would be Earth. But we had a minuscule CO⁠₂ signature compared to Venus. Maybe Astrophage used emission spectra to find Venus?

New plan!

The lab had a seemingly infinite supply of light filters. Pick a frequency, and there’s a filter for it. I looked up the spectral signature of carbon dioxide—the peak wavelengths were 4.26 microns and 18.31 microns.

I found the appropriate filters and built a little box for them. Inside I put a small white lightbulb. Now I had a box that would emit the spectral signature of carbon dioxide.

I put it in the test closet and went out to watch the monitor. Larry, Curly, and Moe hung out on their slide, just like they had all day long.

I flicked on the light box and watched for any reaction.

The Astrophage left. They didn’t just meander toward the light. They were gone. Absolutely gone.

“Um…”

I had been recording the camera input, of course. I ran it back to watch frame by frame. Between two frames they simply disappeared.

“Um!”

Good news: Astrophage were attracted to carbon dioxide’s spectral signature!

Bad news: My three irreplaceable, 10-micron-wide Astrophage had launched off somewhere—maybe at velocities approaching the speed of light—and I had no idea where they went.

“Craaaaaap.”

Midnight. Darkness everywhere. The army guys changed shift to two guys I didn’t know. I missed Steve.

I had aluminum foil and duct tape up over every window of the lab. I sealed the cracks around the entrances and exits with electrical tape. I turned off every piece of equipment that had a readout or LED of any kind. I put my watch in a drawer because it had glow-in-the-dark paint on the hands.

I let my eyes adjust to the total darkness. If I saw so much as a single shape that wasn’t my imagination, I sought out the light leak and put tape over it. Finally, I reached a level of darkness so intense I couldn’t see anything. Opening or closing my eyes had no effect at all.

The next step was my newly invented IR goggles.

The lab had many things, but infrared goggles were not among them. I’d considered asking Steve the army guy if he could score some. I probably could have called Stratt and she would have had the president of Peru personally deliver them or something. But this was faster.

The “goggles” were just the LCD output screen of my IR camera with a bunch of tape around them. I pressed them to my face and added more tape. Then more and more and more. I’m sure I looked ridiculous. But whatever.

I fired up the camera and looked around the lab. Plenty of heat signatures. The walls were still warm from sunlight earlier that day, everything electrical had a glow, and my body shined like a beacon. I adjusted the frequency range to look for much hotter things. Specifically, things over 90 degrees Celsius.