There was a silence, punctuated by bursts of solar static. “Nikka, look, we don’t understand what’s going on. What is that thing?”

“Damn it, I don’t know.” She paused. “No, wait, there’s only one thing it could be. Obviously we’ve never built anything like this. It’s huge, and it looks like a sphere that crashed here. I think it’s related to the Snark.”

“The Snark didn’t leave anything.”

“Are we so sure? Or maybe this was here before. That signal the Snark mentioned, something from the moon, remember? Maybe this was it.”

“Maybe. Look, this is pointless. We’ve got to get something over there to have a look at it and pick you up. That’s what I’ve been worrying about. With all the time we’ve lost, I don’t think we can get any craft to you, even if we can be sure it wouldn’t be destroyed.”

“That’s what I’ve been thinking. I have about half an hour left.” Nikka said the words but she could not believe them. Half an hour was nothing, a long telephone conversation, the length of a news program.

“God, there’s got to be a way out of this. Look, the whole front end is designed to interlock. Can’t you take some of it apart and get at the bottles?”

“When everything was straight it locked. I’ve tried prying things loose and it’s impossible.”

“Those thirty minutes assume movement and exercise. That’s only an average. Why don’t you lie down and relax?”

“I’ll never make it. I might pick up another fifty percent that way, but how fast do you think my metabolism will slow down after something like this?”

“Good point.” There was another drifting silence. There did not seem to be very much more to say. The simple arithmetic came out only one way, no matter how you did it. The toolbox had no torch, so she couldn’t cut away the metal in front.

Alphonsus was saying something, but she couldn’t focus on the voice. She sat and looked out at the rugged plain, dotted with boulders, cratered, sleeping silent in the glaring day. And soon—less than an hour—she would join them. It seemed so incredible; an inch away, just beyond the plastiform faceplate, was total vacuum, total silence, total death. She was a bubble of vapors and fluids, musk and acrid saline tastes, muscles and instincts and life. Only a thin skin separated her from this still world and soon there would be even less distinction.

“Nikka Amajhi. Nikka Amajhi.”

“I’m still here.”

“We’ve been trying to think of something, but—” “There isn’t anything.”

“Is there anything nonregulation on your sled? It isn’t regulation, but you might have taken along a torch or some extra tools or—”

“No.”

“Well”—the urgency crept into his voice—“look around you. There might be something—”

“Wait.” Nikka thought furiously. “I can’t possibly lever the front end off those oxygen bottles. You know why I was chosen to do all this survey work—I’m light, small, so I conserve on fuel. I can’t brute-force my way into anything.”

“Wait… Nikka, we’ve just gotten a squirt from Earth. There’s been a fusion explosion in the northwestern United States. Not a war, apparently. Some kind of accident.”

“So what? I don’t give a damn about that.”

“We might—”

“I’m going to die out here, you bastards!”

“Nikka, look… The point is that Earth wants us to monitor any deep space traffic. In case one of the major powers is pulling something—well, never mind. We’re going to be pretty busy here but we’ll give you all the help—”

“Fine, fine. Just shut up. I’m wondering … This wreck here is a ship, obviously—maybe I can get some help. Break into it. Find—”

“Well, sure, try anything—”

“It’ll probably kill me outright. That’s still better than… I’m going to walk over there now.”

She cut him off before he could say more. Walk to it, no; she ran, knowing the difference in oxygen consumption was not that much. She felt a surge of energy, a quickening of the pulse. It was good to be on the ground again, free, not falling like a helpless wounded bird.

She was so carried away, so sure the coppery thing spelled salvation, that she was totally unprepared when she ran smack into nothingness. Her nose slammed into her faceplate, showering the helmet with tiny red droplets of blood. She fell in a tangle of arms and legs.

She sat up, shook her head. Something buzzed in her ear; her life system, reporting the blood. She worked a control in the back of her helmet and a tape brought a coagulant pill around on a loop near her mouth. She took it, had some water and stopped to think.

It was hard to focus on things. Her head throbbed and there was a gritty taste in her mouth. The impact had destroyed that bounding certainty in her, but she forced herself to get up and stand.

At first she thought she must have stumbled, but no— there were the marks in the dust where she slid backward. She must have hit something. But there was… nothing…

She stepped forward, reached out and felt a definite pressure against her palm. She ran her hand up and down, and to the sides for several meters each way. Something invisible—she almost laughed at the thought—was pushing against her hand. No, not pushing, just there. Solid, a wall. She pulled her hand away and looked at the palm. It had a curious mottled look, clots of brown and orange against the black plastiform.

Partly from caution, but mostly because she needed something to do while she tried to think, Nikka turned and walked back to the sled. The invisible wall was at least a hundred meters from the dome, and she began to have an inkling what it was. At the sled she selected a long piece of tubing wrenched free by the impact and went back to the wall. She thrust the tubing forward, made contact and held it firmly against the pressure. No, it was not a solid wall. She could feel a curious soft resistance to it; the pipe went in slightly and stopped when she could push no harder. She held it firmly, waiting. Nothing seemed to happen. After a few moments she drew it back.

The end of the aluminum pipe was blurred, indistinct. It had melted. Somehow this obstacle was delivering heat to whatever thrust against it.

Despite her impatience she felt a sudden cold fear. Holding the tube against the steady resistance, she turned and walked. The invisible wall did not come to an end. After three minutes of walking she stopped and looked back. Her footsteps described a large, gently curving arc with the dome at its center. She blinked back sweat, feeling it sting her eyes and wishing she could rub them. There didn’t seem to be anything more to do than carry on. She walked further, tracing out the curve of the invisible wall until she came against an outcropping of rocks at the base of the hill. She was no closer to the dome, and minutes had trickled by.

She turned and walked back toward the sled, stumbling in the gray loose rock of the valley floor. She knew with a grim finality that she was never going to reach the dome, would never find anything to help her. Help was far away. She had no way to get to the reserve bottles, even supposing some of them were not ruptured.

A strange feeling of dread and despair rose in her as she looked back at the shattered vessel. Alien. Hostile.

She stumbled again, kicking up dust—was that the first sign of oxygen loss? She bit her lip. First there was an excess of carbon dioxide, they said; her lungs would react to that rather than the lack of oxygen. She stepped over the lip of a small crater. A boulder had rolled into it, crushing the lip on one side. She sagged against the boulder and found a place to sit. She noticed that she was panting. There was a sour, acrid taste to her breath. She hoped it was a sign of fatigue and not something worse. How long did she have? She checked the time and tried to estimate her air consumption rate. No, she couldn’t trust that. She had been running, working—she could have anything from ten to twenty minutes left.