“Some of us who are not completely grown yet.” Fly- in-Amber came drifting out of Mars territory. “Not completely sane . . .” He gently collided with me, as I put my other foot down on the beige spot to anchor us.

“Thank you. Snowbird was not yet two when you humans came. The novelty of it made a huge impression on her unformed mind.”

“You will never win this argument, or lose it,” Snowbird said. “I know you’re wrong, and you know I’m wrong.”

“And since you are wrong, that settles it.” Fly-in-Amber crossed all four arms in a human-looking gesture. “That’s logic.”

Dustin stayed out of it, but I didn’t. “Why does it have to be one or the other, Fly-in-Amber? Your science was fine in the old days, but it wouldn’t get you off Mars.”

“And to the planet of the Others, where we’ll be destroyed along with everybody on Earth, and perhaps in Mars as well? That’s not progress, Carmen.”

“Not the example I would choose,” Snowbird said.

“But it’s relevant,” I insisted. “Human science explained everything pretty well until we met you, and found you had this energy-out-of-nowhere thing. Now we have to fit you into our universe, just as you have to fit us into yours.”

“How can you say that? If you hadn’t stumbled onto us, we could have happily gone on for an eternity, or at least until the cows came home. If we had cows.”

“Was that a joke, Fly-in-Amber?”

“Of course not. I am only trying to adapt to your idiom.”

“He pretends not to have a sense of humor,” Snowbird said, “which makes him even funnier.”

“Idiom,” Fly-in-Amber repeated. “Idiom is not humor.”

“What does the philosopher say about that?”

He grinned. “I have enough for a monograph already.”

“Humans do not understand this, and neither does Snowbird.” Fly-in-Amber made a complex gesture that started him rotating. I reached out and stabilized him. “Thank you. It’s not a concept that I can express in English, or any human language.” He rattled off about thirty seconds of noises in the Martian consensus language. I recognized three clear repeated sounds—one for negation, one for “human,” and one that signals an “if . . . then” statement.

Snowbird was totally still, absorbing it. “Can you translate?” Dustin said.

“Not exactly . . . no. But I could try to say part of it.”

Fly-in-Amber put his small hands together and made a slight bow, perhaps a parody of human gesture.

“It’s about the social function of humor in both races. As if humans were one culture.” Fly- in-Amber barked, and Snowbird answered with a series of clicks. “He points out that you are essentially one culture, in Mars.

“From the first time we communicated—with Carmen, after we decided to let her know we spoke human languages—it’s been obvious that humor both unites and separates the two species. Martian humor is almost always about helplessness, about fate and irony. Humans also recognize this, but most of your humor is about suffering—about pain, loss, death. To us . . . that preference itself is beautifully funny, and is even funnier as you think about it. Like a hall of mirrors, the images fading off into infinity.