Dr. Miller smiled. "No, dear. We drink the water from the pipe. This sample came from the pool."

"But if the animals are in the pool, they must have come from the spring!"

The scientist shook his head. "The spring water is pure. It probably has a lower bacteria count than our well. But the pool water is exposed to the air, and provides an excellent breeding place. Most of these animals propagate from spores, which are in the air."

Rick added, "That's right, Mrs. Miller. When I want a culture I just put some water with a little broth in it out in the open for a day or so, then put it out of direct sunlight. Within seventy-two hours I have a bigger mob of animals than this in every drop."

"Then the Blue Ghost didn't hurt the water of the pool?" Scotty asked.

"Can't tell," Rick explained. "There was no permanent harm done by any chemicals. We can say that much. But you can get a collection like this in three days, and it's been that long since the ghost appeared. So these animals would be in the pool by now, even if the Blue Ghost had done something to adulterate the pool temporarily."

The storm punctuated his remarks with a gust of wind that rattled the windows.

"It's getting worse," Mrs. Miller exclaimed. "I do hope that it doesn't damage the little apples on the trees. They're so good. We're planning to have bushels shipped to Spindrift when they ripen."

Jan Miller brought them back to the subject. "How could chemicals be harmless to the little animals, Rick?"

"Chemicals might kill off those in the pool, but the constant dropping of spring water would soon dilute the solution. Or, some chemicals would combine with the oxygen in the water to form harmless salts. I can't be sure, of course. I'm just trying to think of ways the ghost might be produced."

Barby sniffed. "You're a long way from an answer, I'd say. Even if your old chemicals could make the white mist, they couldn't make the Blue Ghost appear and go through the business of getting shot!"

"Too true, Sis. I'm not claiming a thing. So far we have only some pretty wild speculation, plus an interesting ice-cream man, an offer to buy part of this property, and some missing cement bags. Old ones, too."

Barby had to smile. "If you can tie all those things together into a ghost, I'll type up your science project for free, and as many copies as you need!"

Rick grinned. "And if I don't?"

"I won't be surprised, but you can get me a new record alb.u.m."

"Done. You've got a bargain." Rick turned to Dr. Miller. "There's one bit of information your tenant farmer, Mr. Belsely, can get for us that none of the rest of us can get. That is, do the real-estate agent and the ice-cream man know each other, and in particular, are they friendly?

He could ask around town without causing suspicion."

"I'll ask him right now," Dr. Miller replied. He went to the telephone in the big farm kitchen and dialed. After a moment he said, "Clara?...

Is Tim there?" He waited, then said, "Tim, I have a little job for you.... No, not that. Just asking a casual question around town....

Tim.... h.e.l.lo ..." He hung up and turned to the others. "The phone went dead."

Rick saw that his substage illumination was out, too. "So did the electricity."

Dr. Miller frowned. "It's unusual for both the phone and current to go out at once. That must mean a tree is down across the lines. Both lines cross the creek within a few feet about half a mile upstream."

There was nothing for it but to wait the storm out.

Rick and Dr. Miller resumed their chess tournament. Scotty spent the time making an improvised game of Yoot, an ancient Korean game that can be played almost anywhere, under nearly any circ.u.mstances. At its simplest, the Yoot board can be scratched in the dirt with a stick, and the Yoot throwing sticks that take the place of dice--or a spinning arrow--in similar Western games can be cut from a twig. Scotty sketched the board on a piece of cardboard from a box in which groceries had been carried and made the throwing sticks by splitting a piece of cane from an ancient cane chair in the woodshed. Checkers were used as counters, where in the outdoors pebbles would have served.

"It's like parcheesi," Scotty explained to the girls. "You try to beat your opponent around the s.p.a.ces on the board. The four sticks get thrown into the air, and you can move one s.p.a.ce for every stick that lands flat side up. If all four land flat side up, that's a 'yoot' and you get another throw on top of the four moves. You start, Barby, and I'll show you the other rules as we go along."

At lunchtime Mrs. Miller broiled hamburgers on the charcoal grill out in the woodshed, which connected to the kitchen. Then she used the glowing coals to make coffee in the old-fashioned way, putting the grounds directly into the pan of boiling water. Since the family coffeepot was an electric percolator, this was the only means she had.

Rick would have enjoyed it thoroughly were it not for his impatience to put his plan for catching the ghost into operation. It was certain by now that the affair at the picnic grounds was called off, but with radio and TV silent, there was no way of checking.

The storm continued through the afternoon and into the evening. Dinner was broiled steak, with a tossed salad. If the storm continued for a week, Rick told the group, they'd all get as fat as Collins from Mrs.

Miller's charcoal cooking.

Over coffee he outlined the plan that had been stirring in his mind.

"We don't know the motive for the ghost's appearance yet. We don't know how he appears, either. But unless I'm way off, the Frostola man has something to do with it."

"I don't see how you can say that," Barby objected.

"It's an a.s.sumption," Rick admitted. "But what else have we but a.s.sumptions? We a.s.sume the ghost is man-made. All right. Who's the man?

I give you Frostola, the product that produces ghosts.

"Seriously, we have to make some a.s.sumptions about our chase of the ghost. If it was a man, it was a tall one with some kind of lighted thing on his head. That wouldn't be hard to rig. Plastic comes in all shapes and sizes and colors, these days, including human heads that are used in store windows. It would be a cinch to rig up a flashlight bulb and battery inside one. Wouldn't take me five minutes if I had a little wire and a soldering iron."

"That's true," Dr. Miller agreed. "Making the Blue Ghost the boys chased would be absurdly easy."

"But leading us on took someone who was a good runner," Rick continued.

"He also had to know his way around."

Jan Miller pointed out, "But he floated right over the quarry and you fell in."

"It wasn't like that," Scotty corrected. "We stopped because the ghost had vanished. It's not hard to see why. He switched off the light, walked around the edge of the quarry, then switched on again."

"That has to be it," Rick agreed. "Now, why try to lead us on like that?

It was only an accident that Scotty and I didn't go in together, because his shoe needed tying. Otherwise, we'd both have been at the bottom of the quarry."

Dr. Miller shook his head, in bewilderment, not in negation. "You might very well have been hurt seriously or even killed. In which case people would have blamed the ghost. But why did the ghost do such a thing?"

Rick had wondered about this, too. "I can think of only one reason. The ghost can't stand investigation. He knew we were a menace because Scotty and I ran right up and tried to catch him that first night."

"But why did he tamper with your plane, or try to?" the scientist asked.

"He couldn't have known about the alarm. You checked the plane, didn't you?"

"Yes. It wasn't touched, so far as we could see. Anyway, no harm was done. I can't imagine why he went for the plane, though, unless he figured on sabotaging us that way."

"You still haven't told us why you suspect the Frostola man," Barby pointed out.

Rick ticked off the points on his fingers. "He's new. He arrived just as the ghost started making appearances. But he's not so new that he hasn't had time to study the area or to make plans to lead nosy people to the quarry. He was at the picnic ground when there was no chance of selling much ice cream. He took the cement bags; we don't know why. He's tall and lean, so he could run fast enough to keep ahead of Scotty and me.

He's also tall enough to qualify for the ghost we chased."

He stopped and took a deep breath. "And one more thing. He carries something that would make a marvelous mist for a ghost to appear in.

Something that might harm the microscopic animals in the pool temporarily--although I'm not sure of this--but would be gone with the mist."

The others stared at him with complete interest.

Dr. Miller said softly, "Of course! Rick, that's brilliant. It fits perfectly!"

Jan Miller wailed, "What does?"