The part of the Rio Grande we had reached mimicked the land east of the Big Bend in the real river, an area of steep gorges where the water ran deep and swift. Or at least it did in the brief rainy season. Now, in the middle of summer, it was no trick to wade across. Brenda followed me down the forty-foot cliff on the Texas side, then watched me splash through the river. She had said nothing for the last few miles, and she said nothing now, though it was clear she thought someone should have stopped this massive water leak, or at least provided a bridge, boat, or helicopter. But she sloshed her way over to me and stood waiting as I located the length of rope that would take us to the top.

"Aren't you curious about why I'm here?" she asked.

"No. I know why you're here." I tugged on the rope. It was dark enough now that I couldn't see the ledge, fifty feet up, where I had secured it. "Wait till I call down to you," I told her. I set one booted foot on the cliff face.

"Walter's been pretty angry," she said. "The deadline is just-"

"I know when the deadline is." I started up the rope, hand over hand, feet on the dark rocks.

"What are we going to write about?" she called up at me.

"I told you. Medicine."

I had knocked out the introductory article on the Invasion Bicentennial the night after Brenda and I got the assignment. I thought it had been some of my best work, and Walter had agreed. He'd given us a big spread, the cover, personality profiles of both of us that were-in my case, at least-irresistibly flattering. Brenda and I had then sat down and generated a list of twenty topics just off the tops of our heads. We didn't anticipate any trouble finding more when the time came.

But since that first day, every time I tried to write one of Walter's damnable articles… nothing happened.

Result: the cabin was coming along nicely, ahead of schedule. Another few weeks like the past one and I'd have it finished. And be out of a job.

I crested the top of the cliff and looked down. I could just see the white blob that was Brenda. I called down to her and she swarmed up like a monkey.

"Nicely done," I said, as I coiled the rope. "Did you ever think what that would have been like if you weighed six times what you weigh now?"

"Oddly enough, I have," she said. "I keep trying to tell you, I'm not completely ignorant."

"Sorry."

"I'm willing to learn. I've been reading a lot. But there's just so much, and so much of it is so foreign… " She ran a hand through her hair. "Anyway, I know how hard it must have been to live on the Earth. My arms wouldn't be strong enough to support my weight down there." She looked down at herself, and I thought I could see a smile. "Hell, I'm so lunified I wonder if my legs could support my weight."

"Probably not, at first."

"I got five friends together and we took turns trying to walk with all the others on our shoulders. I managed three steps before I collapsed."

"You're really getting into this, aren't you?" I was leading the way down the narrow ledge to the cave entrance.

"Of course I am. I take this very seriously. But I'm beginning to wonder if you do."

I didn't have an answer to that. We had reached the cave, and I started to lead her in when she pulled back violently on my hand.

"What is that?"

She didn't need to elaborate; I came through the cave twice a day, and I still wasn't used to the smell. Not that it seemed as bad now as it had at first. It was a combination of rotting meat, feces, ammonia, and something else much more disturbing that I had taken to calling "predator smell."

"Be quiet," I whispered. "This is a cougar den. She's not really dangerous, but she had a litter of cubs last week and she's gotten touchy since then. Don't let go of my hand; there's no light till we get to the door."

I didn't give her a chance to argue. I just pulled on her hand, and we were inside.

The smell was even stronger in the cave. The mother cougar was fairly fastidious, for an animal. She cleaned up her cubs' messes, and she made her own outside the cave. But she wasn't so careful about disposing of the remains of her prey before they started to get ripe. I think she had a different definition of "ripe." Her own fur had a rank mustiness that was probably sweet perfume to a male cougar, but was enough to stun the unprepared human.

I couldn't see her, but I sensed her in a way beyond sight or hearing. I knew she wouldn't attack. Like all the large predators in disneylands, she had been conditioned to leave humans alone. But the conditioning set up a certain amount of mental conflict. She didn't like us, and wasn't shy about letting us know. When I was halfway through the cave, she let fly with a sound I can only describe as hellish. It started as a low growl, and quickly rose to a snarling screech. Every hair on my body stood at attention. It's sort of a bracing feeling, once you get used to it; your skin feels thick and tough as leather. My scrotum grew very small and hard as it tried its best to get certain treasures out of harm's way.

As for Brenda… she tried to run straight up the backs of my legs and over the top of my head. Without some fancy footwork on my part we both would have gone sprawling. But I'd been ready for that reaction, and hurried along until the inner door got out of our way with a blast of light from the far side. Brenda didn't stop running for another twenty meters. Then she stopped, a sheepish grin on her face, breathing shallowly. We were in the long, utilitarian hallway that led to the back door of my condo.

"I don't know what got into me," she said.

"Don't worry," I said. "Apparently that's one of the sounds that is part of the human brain's hard wiring. It's a reflex, like when you stick your finger in a flame, you don't think about it, you instantly draw it back."

"And you hear that sound, your bowels turn to oatmeal."

"Close enough."

"I'd like to go back and see the thing that made that sound."

"It's worth seeing," I agreed. "But you'll have to wait for daylight. The cubs are cute. It's hard to believe they'll turn into monsters like their mother."

I hesitated at the door. In my day, and up until fairly recently, you just didn't let someone enter your home lightly. Luna is a crowded society. There are people wherever you turn, tripping over your feet, elbowing you, millions of intrusive, sweaty bodies. You have to have a small place of privacy. After you'd known someone five or ten years you might, if you really liked the person, invite her over for drinks or sex in your own bed. But most socializing took place on neutral ground.

The younger generation wasn't like that. They thought nothing of dropping by just to say hello. I could make a big thing of it, driving yet another wedge between the two of us, or I could let it go.

What the hell. We'd have to learn to work together sooner or later. I opened the door with my palm print and stepped aside to let her enter.

She hurried to the washroom, saying something about having to take a mick. I assumed that meant urinate, though I'd never heard the term. I wondered briefly how she'd accomplish that, given her lack of obvious outlet. I could have found out-she left the door open. The young ones were no longer seeking privacy even for that.

I looked around at the apartment. What would Brenda see here? What would a pre-Invasion man see?

What they wouldn't see was dirt and clutter. A dozen cleaning robots worked tirelessly whenever I was away. No speck of dust was too small for their eternal vigilance, and no item could ever be out of its assigned place longer than it took me to walk to the tube station.

Could someone read anything about my character from looking at this room? There were no books or paintings to give a clue. I had all the libraries of the world a few keystrokes away, but no books of my own. Any of the walls could project artwork or films or environments, as desired, but they seldom did.