Both declined anything to eat. Gantt got a cup of coffee for himself and showed the others where to help themselves to iced tea. They sat at a table under the outstretched flap of the tent, shielded from the sun but open to the fitful breeze.
'Well, Alex, I needn't ask what brings you here, but it is a pleasant surprise.'
Runyan wiped his brow with the back of his hand and scratched his hot beard.
'I've been living with the computer at the Jet Propulsion Laboratory, adapting their orbital programs to calculate the path of a black hole through the earth. When you radioed your results from yesterday to CIA headquarters, Isaacs relayed the essence of it to me. I'd calculated so many orbital eccentricities that I was getting a bit eccentric myself. I'm afraid I was rather obvious about my desire to be out here where the action is, even though that wasn't on the programme. Lord knows I'll just be a fifth wheel.'
'In any case,' continued Runyan, 'I was picked up by an Air Force plane this morning and, much to my pleasant surprise, met Pat here in Yuma.'
'Well, I'm glad to see you both,' admitted Gantt. 'I confess I've been bothered by not having anyone here to talk to about this business. How are your calculations going?' he asked Runyan.
'The model basically fits the data. But there are lots of loose parameters. We don't know enough about the detailed structure of the inner earth and how a small black hole would interact with it to predict small subtle shifts in the orbit with any degree of confidence. A little extra rock, like the roots of a mountain range, can perturb the orbit slightly, depending on angle of approach, a bunch of things. You can get slow cumulative effects, or an occasional finite perturbation. Hard to pin down. The data you're collecting now should allow us to fix some of those parameters. That still won't be the same as proving my picture is right.'
'Actually,' interjected Gantt, 'if we are going to discuss this matter, and I surely want to, we should move over to my tent. It's a little less public there.'
They picked up their drinks and moved off to Gantt's tent which was set off somewhat from the main compound. Gantt went off to gather up two more folding chairs and returned to arrange them in the small patch of shade available.
'Have you learned anything new?' he inquired of Danielson.
'I've collated some more data from the Large Seismic Array and various other monitoring stations. There have been some refinements in our estimations, but nothing qualitatively new.' She took a sip other tea. 'In fact, there's been one major frustration. We had hoped to get the Navy to make systematic measurements of the sonar signal. That would have given us much better positions. Unfortunately, their old data isn't much good now, and they couldn't or wouldn't respond fast enough to get any new data this last week. As a result, the measurements of positions you got yesterday are probably the best we have.'
'Did you explain Alex's hypothesis to the Navy?' Gantt wanted to know.
'No,' replied Danielson, 'the decision was made not to spread that notion any further than necessary until the results of this expedition are in.' She leaned towards Gantt. 'What about this cessation of the signal below the surface which you reported yesterday? My data have never shown a signal from the upper mantle, but you reported a definite time delay. That would be a small effect.in my data which has poor time resolution, but it might be present. I didn't have time to look carefully before hopping the plane. Don't you think it's reminiscent of the sonar signal stopping at the surface of the ocean, just that it starts earlier and lasts a bit longer?'
'Yes, that's my impression,' said Gantt. 'It's strange behaviour for a normal seismic wave, but it might be consistent with Alex's beast as we discussed a La Jolla.' He paused to scratch his head and shuffle his toe in the dirt. 'Still, I can't help wondering whether we could be dealing with some special fissuring that focused normal seismic waves, and those fissures could terminate below the surface.'
'But that wouldn't explain the delay in the return of the waves,' Runyan pointed out, 'nor the holes drilled in Nagasaki and Dallas.'
'Well, maybe the energy is temporarily stored as a mechanical stress in the rock and then released. I admit I don't have a real physical picture of such a process, but neither do I see how to rule out the possibility. The holes? Well, you're right: I can't account for them easily either. Coincidental imperfections in the concrete?'
This rhetorical question went-unanswered. There was silence for a moment, broken by Runyan. 'As I understand from Isaacs, you had a marginal detection of an abnormal acceleration?'
'Yes,' replied Gantt, 'there was some indication in the first event. It could be real, or just an accidental accumulation of noise.'
'From the distances you got yesterday,' Runyan continued, 'what do you estimate for the location of this event coming up today?'
'My best guess is that the epicentre, if you can call it that, will be about a quarter of a mile to the northeast of here, but there's an uncertainty of a few hundred metres.'
'Hmmm, too bad we don't have that Navy sonar data,' Runyan muttered. 'I'd hate to have this thing fly up my ass.' He caught himself and turned to Danielson, patting her on the arm. 'Pardon me, hon, excuse my language.' She suppressed a smile. He turned back to Gantt.
'And you expect it at about 2:03 this afternoon?'
'Give or take a few seconds.'
'So it surfaced almost half an hour ago in northwest Louisiana ,' mused Runyan. 'It's passed through the core and is now headed up to a point in the East Crozet Basin in the southern Indian Ocean. And, after another quick pass through the core, it will soon be here.' He stared down at the brown dirt and scrubby grass beneath his feet, as if by concentrating he could peer into the depths of the earth in reality as he could by imagination and thereby witness this rogue particle at work.
'You think you're right, don't you?' Gantt inquired.
'I'm afraid I am,' Runyan answered.
Gantt stared at Runyan and then removed his glasses and wiped sweat from his eyes. 'Let me give you a tour,' he said and led his guests to the main tent where he explained the function of the arrayed instrumentation.
At fifteen minutes before two, Gantt had Runyan and Danielson stand aside while he made final preparations. Danielson glanced at her watch at two minutes after the hour just as Gantt turned to announce:
'Come and look — I'm getting a signal on the seismometers.' Runyan and Gantt approached and peered over his shoulder. All three seismometers were showing a definite increase in activity. Gantt turned to the computer, fingered the keyboard, and examined the screen.
'I'm getting a good reading on the distance, but I'm having some trouble determining exactly where it's heading since, as predicted, it seems to be right beneath us.'
They turned their attention back to the seismometers which were by now showing great activity.
'Look at this!' exclaimed Gantt. He pointed to the readings on the gravimeters. All were showing a definite and growing anomalous acceleration. Once more, Gantt swivelled in his seat towards the computer, but before he could key in his instructions, confusion erupted.
Runyan first saw the needle of the seismometer in the camp go off scale, slamming against its restraining pin. Before his mind could quite absorb the implication of that occurrence, his body recorded a rapid, bizarre set of feelings. First, he had the definite sensation that the floor of the tent had accelerated upward suddenly like an express elevator. This feeling was terminated by a sideways impulse as if he had been hit with a sudden, strong gust of wind. Just as quickly, that sensation was replaced by a familiar fearsome tickle in stomach and gonads. Runyan was reminded of a roller coaster as it begins its first terrifying descent, leaving tender organs in the grasp of inertia. His ears registered a sucking whistle, rapidly diminishing in amplitude as if someone had turned on a vacuum cleaner just outside the tent and then whisked it rapidly away.
As these sensations passed, Runyan became aware of chaotic shouts beginning to echo around the camp and of Danielson half sprawled, grasping the back of Gantt's chair. Danielson had taken a step towards Gantt and had been caught with one foot m the air when she was bumped sideways and knocked off balance. Runyan helped Danielson regain her feet. She collapsed against him, weak— kneed and pale with shock. Runyan held her shoulders gently.
The whistling noise returned, this time not quite so loud and at a higher pitch. Danielson stepped back from Runyan, her hands on his chest, her eyes searching his for explanation, confirmation. After a moment, Runyan looked towards the instrumentation. Danielson's gaze followed his and they simultaneously swivelled to look at the
