The plan is working. Our Taumoeba are developing nitrogen resistance.

Will they ever be able to handle the 3.5 percent needed for Venus? Or the 8 percent for Threeworld? Who knows? We’ll just have to wait and see.

I’m using percentages here to track the nitrogen. I can only get away with that because in all cases, Astrophage breed where the air is 0.02 atmospheres of pressure. So, since the pressure is always the same across all experiments, I can just track the percent of nitrogen.

The proper way to do it would be to track “partial pressure.” But that’s annoying. I’d just end up dividing by 0.02 atmospheres and multiplying by it again later when dealing with data.

I pat the top of Tank Three. It’s been my lucky tank. Out of twenty-three generations of Taumoeba, Tank Three made the strongest strain nine times. Pretty good, considering she’s got nine other tanks to compete with.

Yes, Tank Three is a “she.” Don’t judge me.

“How long until we reach the Blip-A?”

“Seventeen hours until reverse-thrust maneuver.”

“Okay, let’s spin down the centrifuge now. Just in case we run into trouble and need extra time to fix something.”

“Agree. I go to control room now. You go to storage locker and lie flat. Do not forget control panel with long extension cords.”

I glance around the lab. Everything is firmly secured. “Yeah, okay. Let’s do it.”

* * *

—

“John, Ringo, Paul off,” says Rocky. “Velocity is orbital.”

There is no “stationary” in a solar system. You’re always moving around something. In this case, Rocky reduced our cruise velocity to put us in a stable orbit about 1 AU from Tau Ceti. That’s where he left the Blip-A.

Rocky relaxes in his control-room bulb. He clamps the boxes to their wall mounts. Now that the engines are off we’re back to zero g, and the last thing we want is for the “make ship thrust” button to be floating around unattended.

He grabs a couple of handholds and centers his carapace over the texture monitor. As always, it shows him my center monitor feed with colors represented as textures.

“You in control now.” He’s done his job. Now it’s my turn.

“How long until the flash?” I ask

Rocky pulls an Eridian clock off the wall. “Next flash is three minutes, seven seconds.”

“Okay.”

Rocky’s no dope. He left his ship set up to turn on its engines for a fraction of a second every twenty minutes or so, giving us a much-needed beacon. It’s easy enough to math out where the ship should be. But gravity from other planets, inaccurate measurement of last known velocities, inaccuracies in our estimate of Tau Ceti’s gravity…they all add up to make slight errors. And a slight error on the location of something orbiting a star is a pretty big distance.

So rather than hoping we can see Taulight reflect off the ship when we get to where it should be, he just set it up to flash the engines now and then. All I have to do is watch with the Petrovascope. It’ll be an extremely bright flash.

“What is current nitrogen tolerance, question?”

“Tank Three had some survivors at 0.6 percent nitrogen today. I’m breeding them up now.”

“What spacing, question?”

It’s a conversation we’ve had dozens of times. But it’s fair for him to be curious. His species depends on it.

The “spacing,” as we’ve come to call it, is the difference in how much nitrogen each of the ten tanks receives. I don’t just do the same thing in every tank. With each new generation, I try ten new percentages of nitrogen.

“I’m being aggressive—0.05 percent increments.”

“Good good,” he says.

All ten tanks are breeding Taumoeba-06 (named for the nitrogen percent it can withstand). Tank One is the control, as always. It has 0.6 percent nitrogen in the air. Taumoeba-06 should have no problem in there. If it does, it means there was a mistake in the previous batch and I have to go back to an earlier strain.

Tank Two has 0.65 percent nitrogen. Tank Three has 0.7. And so on all the way up to Tank Ten with 1.05 percent. The heartiest survivors will be the champions, and will move on to the next round. I wait a few hours just to make sure they can breed for at least two generations. Taumoeba has a ridiculously fast doubling time. Fast enough to eat all my fuel in a matter of days, as it happens.

If we get to Venus or Threeworld nitrogen percentages, I’ll do much more thorough testing.

“Flash is soon,” Rocky says.

“Copy.”

I bring up the Petrovascope on the center monitor. Normally, I’d have it off to the side, but the center is the only one Rocky can “see.” As expected, there’s just background light in the Petrova frequency courtesy of Tau Ceti. I pan and tilt the camera. We deliberately positioned ourselves closer to Tau Ceti than the Blip-A should be. So I’m looking more or less directly away from the star. That should minimize the background IR and give me a good view of the flash.

“Okay. I think I have it pointed roughly toward your ship.”

Rocky concentrates on his texture monitor. “Understand. Thirty-seven seconds until flash.”

“Hey. What’s is your ship’s name, anyway?”

“Blip-A.”

“No, I mean, what do you call it?”

“Ship.”

“Your ship has no name?”

“Why would ship have name, question?”

I shrugged. “Ships have names.”

He points to my pilot’s seat. “What is name of you chair, question?”

“It doesn’t have a name.”

“Why does ship have name but chair no have name, question?”

“Never mind. Your ship is the Blip-A.”

“That is what I said. Flash in ten seconds.”

“Copy.”

Rocky and I each fall silent and stare at our respective screens. It took me a long time to notice the subtleties, but I can now tell when Rocky is paying attention to something specific. He tends to angle his carapace toward it and pivot ever so slightly back and forth. If I follow the line he’s pivoting on, that’s usually what he’s examining.

“Three…two…one…now!”

Right on cue, a few pixels on-screen blink white.

“Got it,” I say.