“♪,” he says. Another one-syllable word. The oldest words in a language are usually the shortest.

This time, it’s a chord made of four distinct notes. I enter “two” and record the frequencies for that word.

He starts to get excited. I think he knows what I’m up to and it’s got him happy.

I hold up the “λ” and before I can even speak, he points to it and says, “♫♪.”

Excellent. Our first two-syllable word. I have to scroll back and forth a bit in the waveform data to get the chords right. The first syllable has just two notes and the second has five! Rocky can make at least five different notes at the same time. He must have multiple sets of vocal cords or something. Well, he has five arms and five hands. So why not five sets of vocal cords?

I don’t see a mouth anywhere. The notes are just coming from somewhere inside him. When I first heard him speak, I thought it sounded like whale song. That may have been more accurate than I thought. Whales sound like they do because they move air back and forth across their vocal cords without expelling it. Rocky may be doing the same thing.

Tap-tap-tap-tap!

“What?” I look back at him.

He points to the “λ” symbol still in my hand and then to me. Then back to the “λ” and back to me. He’s almost frantic about it.

“Oh, sorry,” I say. I hold the digit up properly and say, “Three.”

He does jazz hands. I throw some jazz hands back.

Huh. While we’re on the subject…

I stand still for a moment so he’ll know there was a break in the conversation. Then I do jazz hands and say, “Yes.”

I repeat the gesture. “Yes.”

He does it back to me and says, “♫♩.”

I note and record the frequencies in my laptop.

“Okay, we have ‘yes’ in our vocabulary now,” I say.

Tap-tap-tap.

I look over. Once he knows he has my attention, he does jazz hands again and says, “♫♩.” Same chord as before.

“Yes,” I say. “We covered this.”

He holds up a finger for a moment. Then he balls two of his fists and taps them together. “♪♪.”

…What?

“Ohhh,” I say. I’m a teacher. What would I teach someone who just learned the word ‘yes’?

“That’s ‘no.’ ”

At least I hope so.

I ball my fists and tap them together. “No.”

“♫♩,” he says. I check the laptop. He just said yes.

Wait. Does that mean it’s not no? Is that another yes? Now I’m confused.

“No?” I ask

“No,” he says in Eridian.

“So, ‘yes’?”

“No, yes.”

“Yes?”

“No. No.”

“Yes, yes?”

“No!” He balls a fist at me, clearly frustrated.

Enough of this interspecies Abbott and Costello routine. I hold up a finger.

He unballs his fist and returns the gesture.

I enter the frequencies for what I think is “no” into my spreadsheet. If I’m wrong, I’m wrong and we’ll work it out later.

I hold up the “+” symbol. “Four.”

He holds up three fingers on one hand, and one finger on another. “♩♩.”

I make note of the frequencies.

* * *

—

For the next several hours, we expand our shared vocabulary to several thousand words. Language is kind of an exponential system. The more words you know, the easier it is to describe new ones.

Communication is hampered by my slow and clumsy system for listening to Rocky. I check the frequencies he emits with one laptop, then look them up in my spreadsheet on the other laptop. It’s not a great system. I’ve had enough.

I excuse myself for an hour to write some software. I’m not a computer expert, but I know some rudimentary programming. I write a program to take the audio-analysis software’s output and look up the words in my table. It’s barely even a program—more of a script. It’s not efficient at all, but computers are fast.

Fortunately, Rocky speaks with musical chords. While it’s very difficult to make a computer turn human speech into text, it’s very easy to make a computer identify musical notes and find them in a table.

From that point on, my laptop screen shows me the English translation of what Rocky is saying in real-time. When a new word comes up, I enter it into my database and the computer knows it from then on.

Rocky, meanwhile, doesn’t use any system to record what I’m saying or doing. No computer, no writing implement, no microphone. Nothing. He just pays attention. And as far as I can tell, he remembers everything I told him. Every word. Even if I only told it to him once several hours earlier. If only my students were that attentive!

I suspect Eridians have much better memory than humans.

Broadly speaking, the human brain is a collection of software hacks compiled into a single, somehow-functional unit. Each “feature” was added as a random mutation that solved some specific problem to increase our odds of survival.

In short, the human brain is a mess. Everything about evolution is messy. So, I assume Eridians are also a mess of random mutations. But whatever led to their brains being how they are, it gave them what we humans would call “photographic memory.”

It’s probably even more complicated than that. Humans have a whole chunk of our brains dedicated to sight, and it even has its own memory cache. Maybe Eridians are just really good at remembering sounds. After all, it’s their primary sense.

I know it’s too early, but I can’t wait any longer. I get a vial of Astrophage from the lab supplies and bring it to the tunnel. I hold it up. “Astrophage,” I say.

Rocky’s entire posture changes. He hunkers his carapace a little lower. He tightens his claws a bit on the bars he uses to keep in place. “♫♪♫,” he says, his voice more quiet than usual.

I check the computer. It’s not a word I’ve recorded yet. It must be his word for Astrophage. I note it in the database.

I point to the vial. “Astrophage on my star. Bad.”

“♫♩♪♫ ♫♪♫♩ ♫♪♫,” Rocky says.