CHAPTER XIV THE COLD, COLD CLUE THE boys were late to breakfast the following morning. They had fallen into bed, pleased and exhausted, and the noise of the household stirring had failed to waken them.
Mrs. Miller greeted them as they came downstairs. "I hear you were ghost hunting again last night Did you find any?"
"I'll say we did," Scotty replied. "Where is Dr. Miller?"
"Right here," the scientist said from the living-room doorway. "And I have news for you. Collins called this morning and renewed his offer. I told him I'd think about it and let him know later. And Steve Ames called. The powder is definitely carnotite, and it matches ore produced on the Colorado Plateau. Steve has reported to the Atomic Energy Commission, and they'll be able to track down its origin without too much difficulty, since no two ores are precisely alike. Now, how did you two do last night?"
The two girls came into the kitchen in time to hear the question, and Rick almost hated to give the answer, knowing that it would disillusion them, and particularly Barby.
"We trailed three ghosts," he said. "All human."
Scotty added, "And one of them was named Carleton Hilleboe. At least that was the name on the registration of their car."
They told the story in detail while Mrs. Miller and Jan fried eggs and bacon and made toast for their breakfast. Barby listened quietly, but if Rick had any idea she would be convinced, he was mistaken. When the recital ended she pointed out, "There's no reason why mortals shouldn't take advantage of a ghost. You still haven't proved that the ghost at the mine isn't real, or how the cold almost knocked you out last night."
"True," Rick had to admit. "We're not making much progress there."
Over breakfast Dr. Miller told them about the Hilleboes. "They were one of the big families in this vicinity two or three decades ago. They had the biggest house in this part of Virginia, but it burned down about twenty years ago and the kids moved away. There is no house on their land now. They rent some of the land to tenants. Carleton Hilleboe is the eldest son. He's in a business of some kind in Washington. He either controls or owns the property, I'm not sure which."
"Including the upland cornfield above the mine?" Rick asked.
"Yes, and all the property to the east of ours for a mile or two."
"Could he be the mysterious buyer Collins is acting for?" Rick asked.
"It's possible, although why he would want our share of the mine and the field opposite is beyond me. I think a talk with Collins is in order. If you two want to come to town with me, I think I'll beard him in his den. I've no intention of selling, but I won't tell him that."
On the way to town the boys agreed it would be best for Dr. Miller to talk with Collins alone. He obviously didn't like young people - at least them - and he would be more apt to confide in Dr. Miller if the scientist interviewed him alone.
The scientist agreed. "Why don't you two wait in the drugstore? You can have a coke or something."
Dr. Miller parked the car in front of Collins' house and the boys crossed the street to the drugstore. Although it was early in the day, both ordered a dish of ice cream. They were eating it and exchanging small talk with the druggist when the Frostola scooter pulled up outside. Both tensed as the Frostola man came in, but he greeted them impersonally and turned to the druggist. "I'd like a tin of aspirin, please."
"That infected hangnail still bothering you?" the druggist asked sympathetically.
He paid for the aspirin, accepted the druggist's offer of a glass of water, downed two pills, and left.
"Seemed in a hurry," Rick commented.
The druggist nodded. "Seemed so. He usually stops to pass the time of day. Had a terrible time yesterday with an infected hangnail. They can be pretty painful. I tried to sell him a new analgesic ointment, but he insisted on methyl chloride. He had an old refillable prescription from some doctor over in Arlington. Said he got it because infected hangnails bother him all the time. Lucky I had some. It used to be used all the time for pain from superficial wounds, but it went out of style. He bought a whole pint. Enough to last for fifty hangnails. Told him he didn't need it, but he insisted."
Rick said thoughtfully, "His hands seemed to be all right today. No bandages."
"All he had was a plastic-tape bandage around his thumb yesterday, anyway. Guess the infection must have cleared up,"
"What's methyl chloride?" Rick asked.
"A highly volatile chemical. It's not a painkiller in the usual sense, like aspirin. You spray it on the area that hurts, and it evaporates in seconds. You know what that does."
Rick did! And suddenly last night's events were perfectly, transparently clear.
"Evaporation cools the surface," Rick said for Scotty's benefit. "The faster the evaporation, the faster the cooling. This methyl chloride must act pretty fast."
"It does," the druggist agreed. "That's how it kills pain, partly. It chills the outer layer of skin almost instantly."
CHAPTER XV THE MISSING FACTS DR. MILLER'S conversation with Jethro Collins was something less than satisfactory. He told the boys about it on the way home.
"I told him bluntly that I was suspicious about his offer because the property he wants to buy has little value as farm land and contains no timber or anything else of commercial value. I told him I wouldn't consider an offer until I knew what the land was to be used for."
The scientist chuckled. "That was my way of putting him on a spot, of course. But he refused to be cornered. He replied that his customer wanted the land for reasons of his own, which it was not Collins* place to divulge. He assured me the land would not be used for commercial purposes, so my own property would be quite safe.
"I replied that I needed more assurances than his word, and demanded to know the identity of his client. I pointed out that the name would become known during the process of settlement anyway, unless his client proposed to use a dummy of some sort in which to register the deed to the land."
"But he wouldn't tell you the name," Rick guessed.
Scotty offered, "People don't buy land unless it has some value for something. Can't you think of any way in which your land has value?"
"I'm afraid not. I've tried to puzzle it out, with no success. The field itself is all right, if fertilized and limed, but the rest is worthless for farming. There isn't even an access road. The road leading into the picnic area and across the creek to the house is my own property. It's a private road."
Rick kept wondering about the radioactive ore. "Could there be any minerals worth mining?"
"Not even that, Rick. Except for the igneous outcropping in which the mine is located, this whole valley is sedimentary rock, probably for a depth of several hundred feet. Even the foothills are the same kind of rock. They were moved upward from what is now the valley during a shift in the earth's crust. The faults in the formation show this clearly."
"The whole business is tied together somehow," Rick said with conviction. "So far we've been trying to follow threads. We come across other threads that seem to run crossways, but that's because what we're trying to see is a whole piece of cloth, not just the threads. So far we don't know if the cloth is a whole suit or just a handkerchief."
"The metaphor is a little obscure, but I get your meaning, and I agree." Dr. Miller drew to a stop in the driveway of his home. "Suppose we have a late morning bit of refreshment and use our heads instead of our legs?"
At the scientist's request, the girls produced a snack of toast and jam with iced tea and soft drinks. Mrs. Miller begged to be excused from the council because of housework to be done, but the others gathered in the living room to explore the mystery from every angle.
Dr. Miller led the discussion. The scientist was obviously intrigued by the problem, even though he had let the boys handle things in their own way. As he explained with a twinkle, "Rick and Scotty have reputations as detectives to maintain. I'm a poor, simple physicist. No one expects me to solve this mystery. So die boys have to be given first chance to bring the ghost to bay."
Barby sniffed. "You're all pretty sure the ghost is a fake."
"And you're not," Rick observed. "I guess we'll have to put him in a bottle for you before you'll believe it."
"Peace," Dr. Miller interposed. "Each to his or her own opinions. We're here in pursuit of facts, not fancies. Rick, you're first at bat."
Rick considered. What were the most important facts? They had been working on assumptions, but assumptions need proof before they can be accepted as valid.
"Well, I'm not sure I'm listing the facts in order of importance, but I'll try. First, the ghosts that walk the fields at night are humans."
Barby interrupted. "How can you be certain?"
"They looked human. We saw their silhouettes against the sky clearly enough to see their shapes, and they were human shapes." As she started to speak again, he held up his hand. "Whoa! Let me finish. Ghosts also have human shapes is probably your counterargument. I'm not arguing that ghosts don't really exist, but if they do, they are supposed to be sort of nonsolid, aren't they? Like the Blue Ghost at the mine. But the field ones were solid enough. No light showed through them."
"And you've no proof the ghosts you saw in the field came from the car," Barby defended hotly. "Did you see them get in the car and drive away?"
Scotty held up his hands in surrender. "No. I passed them on my way back from the car."
"Evidence not sufficient," Dr. Miller said with a grin. "The ghosts may or may not be human. Your first fact needs more proof, Rick. Carry on."
Back sighed. "All right. I'll start over again. First, we have uncovered cement bags that contained radioactive ore, pulverized into a fine dust. I'll amend that. The bags contain a small quantity of radioactive ore, which gives some reason for believing they were once full of such ore."
The group laughed. "Now you're on the beam," Dr. Miller approved. "State only what you know as fact and identify what you infer from the facts as inference or speculation."
"Glad you all approve. Second, we believe the Frostola man was interested in the cement bag Scotty carried. It is a fact that when we returned from town the cement bag that we put in the trash can, and the cement bags we left where we found them, had been removed. Because of the Frostola man's apparent interest, we are of the opinion he took the bags."
Jan Miller giggled. "You sound like a lawyer."
"I feel like one," Rick returned with a grin.
"Third, the Blue Ghost led Scotty and me on a wild chase that ended up with me dropping into the quarry. The facts are that the ghost somehow triggered the plane alarm. We will not argue whether or not a real ghost could have set off a purely physical, nonspiritual alarm."
Barby nodded soberly, but there was a twinkle in her blue eyes.
"Continuing with the facts of that incident, the ghost stayed ahead of us without difficulty. A real ghost could have done that, I suppose, but so could any person in reasonable physical shape who knew the terrain. Now, the ghost's light went off as he reached the edge of the quarry, or somewhere in the vicinity of the edge."
Rick looked at his sister. "I will stipulate that a real ghost need not have any reason for his actions. But a person imitating a ghost would have had to turn off his light in order to go around the quarry, otherwise we would have seen that he made a detour. A ghost would presumably float right over the quarry."
"Ghosts do float," Barby agreed solemnly.
"Uh-uh. Since this one did not, and since it reappeared - or the light did - on the opposite side of the quarry, we believe there was a deliberate attempt to lead us into said quarry."
He paused and took a deep breath. "How am I doing, coach?"
Dr. Miller nodded approval. "Fine. See how easy it is to separate fact and conjecture?"
"So what do we conclude from this one event? We conclude it is reasonable to believe that a person, and not a spook, triggered the plane alarm and led us to the quarry. We speculate that the person did not know about the alarm and set it off by accident, probably while inspecting the plane, since we see nothing to be gained by sabotage. We speculate that the chase was to frighten us, not primarily to harm us, the reason being that we rushed the ghost during the ghost act and are therefore potentially dangerous. We reach this conclusion because the ghost picked a side of the quarry where we would land in the water, which is plenty deep by the way, and not on the rocks."
"Okay. Scotty, take over. I'm worn out from trying to be precise."
The scientist grinned. "Lack of practice, I'm afraid. If we all sought precision in our speech many of the world's misunderstandings could be avoided."
"I don't know what we can say," Scotty objected. "We have few facts. We have only some observations. We can try to interpret our observations, but we can't prove them. For instance, there is the fact that we were given a bath of something by the Blue Ghost that seemed to freeze our faces. There is the fact that the Frostola man bought a quantity of methyl chloride. There is the fact that methyl chloride could have produced the effect we felt. But how can we say that it's a fact that the Frostola man somehow doused us with chemical?"
"You can't," Jan Miller agreed.
"So if we stick to demonstrable facts, we don't get far," the scientist concluded. "But can we settle for mere speculation?"
"No, sir," Rick stated. "But let's admit that speculation has its uses. After all, circumstantial evidence is permitted in court. Speculation can give us the circumstances that need to be proved, and that tells us where to put our efforts. I think that's fair enough."
"So do I," Dr. Miller agreed.
Rick arose. "Then we'll continue working the way we've been doing it. It's not the best way, but at least we're uncovering little items that can be tied together if we find just two missing facts."
"Like what?" Barby demanded.
"We go back to our assumption that the ghost is man-made. On this assumption, the things we need to know are how and why is the ghost produced?"
CHAPTER XVI TRAPPED! IT WAS, as Rick said, time for action and not for words. He and Scotty set out to track down every possible shred of evidence. They armed themselves with flashlights, and Rick made sure he had his pocket lens, and they started out.
The first stop was in the field, to locate the places where last night's ghostly party had paused.
As the boys walked across the field toward the plane, Rick wondered aloud. "What did the ghost want with the plane?"
Rick considered. "It could be, I suppose, but we've examined the whole area from the plane. I didn't see anything suspicious or particularly interesting."
"Not a thing," Scotty confirmed. "But it might be a good idea to take another look."
"Okay. We can do it later this afternoon. Now, according to what I remember, the first stop the ghosts made was right about here. Let's work like hunting dogs and see what we can turn up."
Rick dropped his handkerchief on a clump of bachelor's-buttons for a marker, then he and Scotty walked in ever-widening circles, scanning the ground for any trace of the ghosts.
Scotty's keen eyes saw the first sign, a heelprint in a bare place in the grass. The boys examined it. "Doesn't match anyone's shoes," Scotty said. "Not of our gang. Leather heels, a little worn, run down on the outside edge. You can see the nail marks. No rubber heels would make those marks."
There were other prints, now that they were searching closely. Clearly, three men had walked the field last night. But nowhere did they find a clue to what the men had searched for. There was no raw dirt, no impressions left where something had been removed.
"Fact," Rick stated. "Three men were here."
Scotty laughed. "This does not mean there were not also three ghosts who left no tracks."
Rick had to laugh, too. "Now what do we do?"
"Look in the upland cornfield."
They started the survey of the cornfield directly above the mine entrance, where they had first seen the three ghosts. Tracks were visible almost at once.
"We're lucky," Scotty said. "Even with the weeds between the rows there's enough bare ground so we can do some real tracking. Let's see how the tracks run."
As Scotty had predicted, the tracking was much easier. A few yards into the cornfield they came to a gap where a few seeds had failed to germinate or the plants had died. It was a bare space, sparsely grown with weeds.
Scotty pointed to the three sets of tracks, and put his own feet in one set, while Rick did the same with another set. From the position of the third set it was clear that the three men had faced each other.
Rick said excitedly, "They paused and bent over. But over what?"
They scrutinized the ground minutely. It seemed normal enough. There was absolutely no sign that the earth had been disturbed.
Rick picked up a handful of soil and examined it. "Dirt," he said. "Plain dirt. Why was it so interesting to the spooks?"
"Try your lens," Scotty reminded him.
Rick did so. The lens showed the usual combination of mineral and organic matter of various sizes and colors. "I can't see anything unusual," he reported. "Maybe the lens isn't powerful enough. I'll take a sample and look at it under the microscope later." He found a scrap of paper in his wallet and folded a bit of dirt into it.
"Let's continue," Scotty urged.
They worked their way across the cornfield, following the tracks. Twice more they found places where the ghosts had paused to confer about something, or examine something.
Then, at the edge of the cornfield, they lost the tracks in a rank growth of weeds. Probably the ghosts had trampled the weeds last night, but they had sprung up again and left no trace of the passage.
Scotty took the lead. "I'll show you where the car was parked."
They traveled through alternate weeds and hay to where the hilltop dropped away rapidly to a valley about three hundred feet below. This marked the end of the igneous outcropping in which the lead mine was located, Rick guessed. The hill was steep, and overgrown with blackberry bushes.
"I got caught a thousand times in as many feet last night," Scotty commented. "It's easy by day, but don't try it by night." He led the way through clear spaces between the thorny patches, always going downhill.
It wasn't long before Rick saw the road, if it could be called that. It was two ruts with grass growing between them.
"Doesn't look like U.S. Highway Number 66," he remarked.
"There's a man who thinks it is," Scotty replied.
Rick looked to where his pal pointed. The Frostola man was approaching on his scooter. The sound of the little motor was just audible, and Rick's first impulse was to duck, but Scotty said, "Too late. He saw us just as we saw him. Let's walk down to the road and make it casual."
They did so, and the peddler approached, bumping over the uneven surface.
"Howdy," he greeted them. "Where does this road go?"
"We don't know," Scotty replied.
Rick added, "We're strangers in the area."
"I'm pretty new myself," the man said cheerfully. "Saw this road and thought there might be a settlement where I could find some new customers."
"We don't know of any," Rick said.
"Looks like I might as well go back to town, then. Want a lift? You can hang onto the step behind me."
"No, thanks," Scotty replied. "We're staying just over the hill."
The Frostola man turned his scooter wagon, gave them a wave, and went on his way back toward town. The boys watched until he drove out of sight.
"There's an optimist," Scotty said. "Follows a pair of ruts, hoping to find civilization at the other end."
Rick grinned. "He certainly likes this part of Virginia. There's one thing about peddling Frostola here-"
"No customers to bother you. It's easy to commune with Nature."
"Aye-aye. Does he look like a nature lover to you?"
"Now that you mention it, I've seen people who fitted the part better. We scared him away, that's for sure. But what was he doing here?"
Scotty considered. "If he wanted to reach the mine area without people noticing him, he could park his scooter here and walk over the hill."
"He could," Rick agreed. "But why would he want to reach the mine area?"
"Not to sell Frostola. That's for sure."
"Uh-uh. My guess is he has to reset the Blue Ghost."
"Sure. Think about it. The projector can't go on operating forever when a clock reaches nine, can it? It must need servicing and resetting."
"And loading with methyl chloride to squirt at us?"
"Too true." Rick had wondered about that. "But how does the chemical squirter work? Where is it? The projector must be close to the Blue Ghost, if the chemical came from the same place."
Scotty laughed. "You don't discourage easily, do you? We tried to find a projector beam the other night, remember? What did we get for it? A squirt in the face. No projector, no nothing."
"There has to be a projector, or an imagemaker of some kind," Rick insisted, "unless you're admitting the ghost is real."
"Where would it be located?"
"Very close, I'd guess. Hidden somewhere near the spring pool, batteries and all. It has to be, and I think we'd better spend some time looking."
"Starting where? Don't tell me - it has to be the mine."
Rick was already walking back up the hill toward the cornfield. "There's no other underground location in which a projector could be stored, is there? So let's get at it."
"Glad we brought flashlights," was Scotty's only comment.
They hiked in silence to the cornfield, pausing now and then among the corn plants to examine footprints. Thanks to the rain that had left the ground soft, there were plenty of them, but they told the boys no more than they already knew.
At the top of the hill above the mine they paused to survey the scene. Belsely was hauling a load of rock through the field near the plane, using his tractor and a stoneboat. The boys knew he was busy building a stone fence. He saw them and waved. They waved back, then went down the hill to the spring and its basin.
Again they examined the entire location with great care, and Scotty probed seams in the rock with his jackknife blade. The entire hillside in this location was cracked and seamed and the rock face above the basin was rough and irregular. Rick wondered if there had ever been an earthquake in the neighborhood or whether the settling of the earth into the mine has caused the cracking.
"Nothing here," Scotty said. "At least nothing I can see. We'll have to try the mine itself."
They had replaced the boards at the entrance, simply pushing the nails back into the holes from which they had come. They pulled the boards aside and saw footprints - and not their own!
"Visitor," Scotty said with excitement.
Rick noted the size of the tracks. "And a big-footed one, too. Makes our tracks look small."
Scotty pointed. "He came out again, whoever he was. Let's see how far he went in."
The tracks told the story clearly and quickly. The visitor had gone in about twenty feet, and had then returned to the outside. One glance told the boys why.
The mine was timbered, with uprights and overhead beams spaced about every ten feet. Where the visitor had stopped, the mine timbers were supporting a big piece - or many pieces - of the rock overhead. Rick guessed that the heavy rain, working through cracks, had loosened a section and let its weight fall on the overhead crosspiece. It was also clear that the timbers would not support the weight for very long. They were rotten, and wet with the constant seepage of water.
"Must have been one of the Sons of the Old Dominion who wandered in for a look," Rick suggested. "He saw it wasn't safe and went right out again."
"Something like that," Scotty agreed. "And it isn't safe. Those timbers would go if anyone breathed hard at them."
'Then let's not breathe hard," Rick said.
"Meaning that we're going in, anyway."
Rick pointed out, with what he thought was complete logic, that the timbers had held the roof up since the rain, and that collapse surely wouldn't take place in a minute or two. He concluded, "And if we're going to find any kind of clue to a projector, it has to be in this mine somewhere."
"Then let's not linger," Scotty said. "And for Pete's sake don't stamp your feet when you go by the timbers. A little vibration would send them down for sure."
Rick asked, "What were the wind and the laughter the last time we were in here?"
"Imagination," Scotty replied. "Let's keep it under control this time."
"I'm with you. And ghosts don't blow out flashlights, so let's go."
They moved cautiously past the unsafe place, lights probing the tunnel walls for a sign of anything unusual or worthy of attention. Now and then they reached a bay where ore had been taken out, or a jog in the tunnel where the miners had lost the ore vein temporarily. They reached the spot of their penetration into the mine on their last visit and found the remains of their torches.
"No change. Thought they might have been chewed by ghosts," Scotty commented.
"Newsprint doesn't taste good," Rick replied. "Do ghosts have teeth?"
"Nope, just an icy breath. Do you remember any smell, by the way? When we got hit in our faces?"
"Something sort of sweet?"
"Yes. I wasn't thinking about smelling, and I didn't notice especially, but I sort of recall a nice odor."
Rick thought he remembered it, too. "We'll look up methyl chloride in the dictionary," he promised. "That will tell us if it has an odor."
The mine took a sharp turn. "They lost the vein here and had to chew out some rock to find it again," Rick pointed out. "Notice everything is on one level?
Must have been just one vein. It ran out and the mine closed down."
"Looks that way," Scotty agreed. "How far have we come?"
Rick hadn't kept track, but he estimated they were perhaps halfway under the hill. "This must end somewhere," he said. "Notice there isn't any water at all, not even seepage? I'm still baffled by that spring and the pipe."
They traversed another hundred yards in silence, flashlights constantly scanning the mine. There was nothing out of the ordinary, no sign of ghost, projector, or even of human visitation for dozens of years.
"We're on another wild-goose..." Rick began. He never finished, for sound suddenly reverberated through the mine, the sound of rock crashing downward.
Both boys turned and ran back toward the entrance, afraid of what they would find. Long before they reached it, billowing clouds of dust told them what had happened.
Their racing legs confirmed it as they came to a stop against rock that choked the tunnel from top to bottom.