“I’m not saying this well. But for most of us, humor is absolutely necessary for survival—if you lived in a small hole in the ground, and knew there would never be anything else, you would perhaps feel the same way.”

“Sort of like what we call ‘gallows’ humor,” Dustin said.

“ ‘Ask for me tomorrow,’ ” Fly-in-Amber quoted, “ ‘and you will find me a grave man.’ ” He said it with a British acting voice. “That was a BBC radio production of Romeo and Juliet in 1951. Very Martian humor. Mercutio has been stabbed, and he jokes about dying. Most human humor is not so clear to me.”

“Nor as funny,” Snowbird said. “So many jokes about people falling down, which is hardly possible with four legs. Sex jokes aren’t funny because we have to figure out what the people are doing, and why that’s more funny than what they normally do.” She turned to Fly-in-Amber and made the thumping laughter sound. “Only two people! Only two!”

“Some of us don’t think that’s funny,” Fly-in-Amber said. “They can’t help the way they’re made.”

“Do you tell jokes about Martian sex?” Dustin asked.

Snowbird pantomimed scratching her head, which was kind of funny, avoiding all the eyes up there. “No . . . no fate or irony or helplessness there. What is there to laugh about?”

“Trust me,” he said. “Humans find Martian sex pretty entertaining.”

“But it’s so plain and innocent, compared to human sex. We don’t hide away and do it in private, and kill people if they do it with the wrong person.”

“You’d never have a Shakespeare,” I said.

“I think we do have individuals like Shakespeare,” Fly- in-Amber said. “Though it would be difficult to explain, to translate, what I mean by that.”

“I should think so. Since you don’t seem to have anything like drama.”

“Nothing dramatic used to happen to us, before you came. I suppose we’re going to need drama now.”

“And psychoanalysis,” Dustin said. “Social workers. Police and jails.”

“We look forward to evolving.”

PART 2

THE PLANT

1

GRAVITY SUCKS

On Earth we’d seen pictures of the iceberg, and so didn’t expect it to look like an iceberg, glistening and pure. I was once stationed in Greenland in the winter; it looked something like that, cold and dirty. Elza said it reminded her of North Dakota in the winter—windstorms drive dark topsoil to mix with blizzard snow to make a black substance they call “snirt,” neither snow nor dirt.

It was the fossil nucleus of an ancient comet. Billions of years ago, Mars had bent the thing’s orbit around, turning it into a small asteroid of ice and impurities, never to be warm enough to have its day in the sun and grow a magnificent tail.

So it was a huge dirty snowball, somewhat out of round. White splashes where engineers and their robots had blasted and drilled to turn it into a huge fuel tank. It provided reaction mass for the main drive and an array of small steering jets, mainly for turning us around at midpoint—and evading rocks, if it came to that.