Earth

As he spoke, both little loops made lopsided figure eights and broke into four tinier ones, vibrating madly. Each of these soon divided again. And so on. As they multiplied, their size diminished and brightness grew — bound for a

“So,” George surmised. “Small ones still aren’t dangerous.”

Alex nodded. “A simple, chaotic string like this couldn’t explain the power curves at Iquitos. So I went back to the original cavitron equations, fiddled around with Jones-Witten theory a bit, and came up with something new.

“This is what I thought I’d made, just before Pedro Manella set off his damned riot.”

The tiny loops had disappeared in a blare of brilliance. Alex uttered a brief command, and a new object appeared. “I call this a tuned string.”

Again, a lambent loop pulsed in space, surrounded by white sparks of particle creation. Only this time the string didn’t twist and gyre chaotically. Regular patterns rippled round its rim. Each time an indentation seemed about to touch another portion, the rhythm yanked it back again. The loop hung on, safe from self-destruction. Meanwhile, matter continued flowing in from all sides.

Visibly, it grew.

“Your monster. I remember from when you first arrived. I may be drunk, Lustig, but not so I’d forget this terrible taniwha.”

Watching the undulations, Alex felt the same mixed rapture and loathing as when he’d first realized such things were possible… when he first suspected he had made something this biblically terrible, and beautiful.

“It creates its own self-repulsion,” he said softly, “exploiting second- and third-order gravities. We should have suspected, since cosmic strings are superconducting—”

George Hutton interrupted, slapping a meaty hand onto Alex’s shoulder. “That’s fine. But today we proved you didn’t make such a thing. We sent waves into the Earth, and echoes show the thing’s dissipating. It’s dying. Your string was out of tune!”

Alex said nothing. George looked at him. “I don’t like your silence. Reassure me again. The damned thing is for sure dying, right?”

Alex spread his hands. “Bloody hell, George. After all my mistakes, I’d only trust experimental evidence, and you saw the results today.” He gestured toward the mighty thumper. “It’s your equipment. You tell me.”

“It’s dying.” George said, flat out. Confident.

“Yes, it’s dying. Thank heaven.”

For another minute the two men sat silently.

“Then what’s your problem?” Hutton finally asked. “What’s eating you?”

Alex frowned. He thumbed a control, and once again a cutaway view of the Earth took shape. Again, the dot representing his Iquitos singularity traced lazy precessions among veins of superheated metal and viscous, molten rock.

“It’s the damn thing’s orbit.” Equations filed by. Complex graphs loomed and receded.

“What about its orbit?” George seemed transfixed, still holding the bottle in one hand, swaying slightly as the dot rose and fell, rose and fell.

Alex shook his head. “I’ve allowed for every density variation on your seismic maps. I’ve accounted for every field source that could influence its trajectory. And still there’s this deviation.”

“Deviation?” Alex sensed Hutton turn to look at him again.

“Another influence is diverting it. I think I’ve got a rough idea of the mass involved…”

The bigger man swung Alex around bodily. The Maori’s right hand gripped his shoulder. All signs of intoxication were gone from Hutton’s face as he bent to meet Alex’s eyes.

“What are you telling me? Explain!”

“I think…” Alex couldn’t help it. As if drawn physically, he turned to look back at the image in the tank.

“I think something else is down there.”

In the ensuing silence, they could hear the drip-drip of mineral-rich water, somewhere deeper in the cave. The rhythm seemed much steadier than Alex’s heartbeat. George Hutton looked at the whiskey bottle. With a sigh, he put it down. “I’ll get my men.”

As his footsteps receded, Alex felt the weight of the mountain around him once more, all alone.

□ In ages past, men and women kept foretelling the end of the world. Calamity seemed never farther than the next earthquake or failed harvest. And each dire happening, from tempest to barbarian invasion, was explained as wrathful punishment from heaven.

Eventually, humanity began accepting more of the credit, or blame, for impending Armageddon. Between the world wars, for instance, novelists prophesied a

Apocalypses, apparently, are subject to fashion like everything else. What terrifies one generation can seem obsolete and trivial to the next. Take our modern attitude toward war. Most anthropologists now think this activity was based originally on theft and rape — perhaps rewarding enterprises for some caveman or Viking, but no longer either sexy or profitable in the context of nuclear holocaust! Today, we look back on large-scale warfare as an essentially silly enterprise.

As for starvation, we surely have seen some appalling local episodes. Half the world’s cropland has been lost, and more is threatened. Still, the “great die-back” everyone talks about always seems to lie a decade or so in the future, perpetually deferred. I

Has the Apocalypse vanished, then? Certainly not. It’s no longer the hoary Four Horsemen of our ancestors that threaten us, but new dangers, far worse in the long run. The by-products of human shortsightedness and greed.

Other generations perceived a plethora of swords hanging over their heads. But generally what they feared were shadows, for neither they nor their gods could actually end the world. Fate might reap an individual, or a family, or even a whole nation, but not the entire world. Not then.

We, in the mid-twenty-first century, are the first to look up at a sword we ourselves have forged, and know, with absolute certainty, it is real…

• EXOSPHERE

“All right, babe. The first elevator heading down will be crammed with cargo, but Gle

“ — of pure titanium. Yeah, I know that one.” Teresa laughed, glad to share even a weak, tension-melting joke.

So far, so good, she thought. Right now it felt great just looking at him, knowing he was a mere forty kilometers away, and soon would be much closer. Jason, too, sounded eager to give this a try.

Someone had once told Teresa it was too bad about her husband’s smile, which sometimes transformed his intelligent features into those of an awkward puppy dog. But Teresa found his grin endearing. Jason might be insensitive at times — even a jerk — but she was sure he never lied to her. Some faces just weren’t built to carry off a lie.