I found a depth where I could stand on the bottom and keep the tip of the airway just above the surface. The taste of it was sour in my mouth. I had washed it since the Landing, washed it over and over again; but I still imagined I could taste the rusty flavor of blood on the plastic.

Trying to refocus my thoughts, I aimed the Bumbler's scanner straight up at the outside world. In the muddy water, I had to amplify the Bumbler's brightness before I could make out the screen; but my eyes adjusted soon enough to give me an adequate view above the surface.

The sky. The creek banks.

Thirty seconds after we had hidden ourselves, a head peeked over the south bank.

At first, it looked like a fully human head: smooth brown skin; darker lips. But as I stared more closely, bile rose in my mouth. The head had no hair — or rather it had an abstracted glass simulation of hair, like Oar's but a slightly different style… and the eyes were also like Oar's, silvery globes with mirror surfaces.

The lips drew back in smile… or maybe a grimace. Inside the mouth, the teeth were clear as glass.

Sickened, I realized what I was seeing. This was a glass person just like Oar; but he or she had glued strips of skin onto cheeks, forehead, and throat.

Strips of human skin.

Hiding

The skin-covered face peered down a few seconds more, then withdrew. I stayed put, hoping Oar would do the same — she was under orders not to come out until I gave the okay. Still, she had only a brief supply of air, and was inexperienced using a scuba breather; I gave the signal to surface at the two minute mark, even though I would have preferred to stay under much longer.

Oar emerged silently and kept her mouth shut. Good; no matter how she might be given to outbursts, her cultural heritage placed priority on not being noticed. They built their villages underwater, they made themselves transparent, they cleaned all trace of their presence from the environment… no wonder Oar had the instinct to stay quiet when strangers were near.

I wondered if Skin-Face was the reason Oar's people were so good at hiding.

For five minutes we remained in the water with only our heads showing. All that time, some devil's advocate in my mind kept asking why we should cower. The skin on that glass face was probably just animal hide — perhaps leather from a buffalo carcass, scraped clean of fur and worn for harmless adornment. Believing it was human skin was morbid imagination… that and the blurriness of looking at the Bumbler screen through muddy water.

But if it had been human skin, it came from an Explorer, not someone with a glass body. And perhaps the accompanying radio transmissions had come from Explorer equipment: equipment stolen from my fellow ECMs along with their skins.

I made myself get out of the water when I could no longer control the chattering of my teeth — not fear, but the physical chill of a creek in waning autumn. For a while I shivered on shore, until the sun warmed me back to a tolerable temperature. Thank heavens R D made the tightsuit from quick-dry fabric; I would only stay soggy for half an hour, after which the material's natural insulation would be as good as a dry parka. In the meantime, I had to hug myself for warmth and wonder if Skin-Face would reappear.

He didn't… or possibly she didn't, although I was inclined to think of the stranger as male. Some atavistic prejudice in my subconscious still believed men were scarier than women.

Say it was a man, a glass man of Oar's species: he must have heard the Bumbler's alarm beeping and came to investigate. It had taken him more than a minute to arrive, so he hadn't been nearby… close enough to hear it, but far enough away that he hadn't recognized the sound as unnatural. When he saw nothing out of the ordinary, he must have decided the noise was just bird cry. One quick look, then he went back about his business.

What was his business? It was time to find out.

It was also time to get the stunner out of my pack.

Three Spears

Motioning Oar to stay put, I swam the creek with the stunner in my mouth, in case I might need it quickly. The afternoon continued quiet and undisturbed — the chirp of birds, the light hiss of breeze ruffling the prairie grass. On the far side of the water, I climbed the dirt bank: steep, but only three meters high, the damp earth providing plenty of purchase. When I was almost at the top, I dug my feet firmly into the soil and did a quick scan with the Bumbler, X-raying through the last few centimeters of bank to make sure Skin-Face wasn't lurking above. The screen was clear except for pebbles and roots; so with straining caution, I lifted my head over the edge for a look.

No Skin-Face close at hand; but a kilometer downstream, three humanoid figures tracked along the bank, walking away from me. The Bumbler gave me a telescopic view of the trio: three males, all carrying spears and shoulder bags, all wearing strips of skin on their faces. They had skin on their genitals too, carefully wrapped around penis and testicles. One also had a patch of skin on his chest — I could see it through his transparent back.

Perhaps that was the chieftain: the man who could commandeer the largest share of a kill.

Still hoping I was wrong, I magnified the view a few notches higher. Maybe the skin strips were some kind of harmless ornamentation…

No. In extreme close-up, there was no mistake. It was brown human skin, complete with wisps of hair, fastened to the underlying glass flesh.

One man lifted his hand and pointed at the creek ahead of them. The chieftain nodded, and all three started down the bank toward the water. My guess was they had reached a point shallow enough to ford; they were obviously reluctant to cross where the creek was over their heads. That gave me useful intelligence about the enemy… and already I was thinking of them as enemies, although they had showed no sign of hostility toward me or anyone else.

Explorers habitually regard strangers as threats. Shaking hands is for diplomats.

Simple Prairie Hunters

The men appeared on the far side of the creek a short time later and continued north. On their present path, they would run into the buffalo herd we had seen that morning… and that might be their goal. They might be simple prairie hunters, searching for food to feed their families.

Simple prairie hunters who carried radios.

I shook my head to clear it. Explanations would come eventually… or else they wouldn't. Unsolved puzzles were a permanent frustration of the job.

At last the spearmen disappeared behind a copse of trees and I waved for Oar to join me. She crossed the creek with the scuba breather in her mouth, even though it couldn't have much air left in it. I didn't say anything — if she was happier to get air from a machine rather than holding her breath for the few seconds the water was over her head, so be it. The little tank was self-charging, given enough solar energy and access to air; in twenty-four hours it would be usable again.

From the top of the bank, I led us straight to the nearest clump of trees, to make sure we were shielded from the spearmen's eyes — even though they were more than a klick away, the prairie allowed for long sight-lines. The men had come from this direction; we found their footprints in the dirt when we stopped to collect ourselves.

One good thing about people as dense as glass: they leave deep, clear footprints.

"Who were those people?" Oar blurted when we were safely under the trees.

"I was going to ask you the same question," I answered. "You don't know who lives in this area?"