The five jeeps were lined up outside. Rick carried out a transit, the tripod slung over his shoulder, and found the two local helpers waiting.

Ruiz was a short, swarthy man with gleaming white teeth and a Mexican-style sombrero. Honorario was only slightly taller, and so thin a strong breeze would blow him away. The two San Luzians greeted him courteously. "_Buenos dias, senor._"

Rick knew enough Spanish to be equally polite. "_Buenos dias, senores.

Como estan ustedes?_"

The two switched to English. Rick hoped it wasn't a reflection on his Spanish accent, acquired at Whiteside High School the year before. "We are well, senor," Ruiz answered, and Honorario added, "We hope you will enjoy San Luz, senor."

Rick said that he expected to enjoy it very much indeed. He wondered if the two knew that their mountain was getting ready to blow its top. He asked, "Do you have the dynamite, _amigos_?"

"In the shed, senor. Also the caps and the detonators. If you will come, I will show you." Ruiz gestured toward a concrete shed that stood some distance away.

"What was the shed used for?" Rick asked as they walked toward it.

"It is a shed for a pump, senor. The pump is for the hotel's water, which must be brought up the hill from Calor."

In a moment Rick saw for himself. The pump was operating noisily. Along one wall were shelves, one of which contained two cases of dynamite and boxes of caps. On another shelf were three detonators. He selected one, then picked out six sticks of dynamite. He handled the stuff gingerly, even though he knew it was safe as so much soap. Dynamite, for all its explosive power, is stable stuff, and difficult to set off by accident.

The dynamite caps were much less safe, however. Each was packed carefully in its own protective wrapping, but Rick took no chances. He put each one in a different pocket. Then, feeling like a keg of gunpowder with a sputtering fuse, he walked back to the jeep.

Hobart Zircon and Scotty came out of the hotel as he approached.

"Stand back," Rick said grimly. "I may go off like the Black Tom explosion if you touch me."

Big Hobart Zircon chuckled. "Don't worry, Rick. If you do, we'll go off with you. Would it make you happier if I carried the explosives?"

Rick considered. "It doesn't matter," he said. "If the stuff goes off, we'll all go into orbit at the same time and the jeep will go with us.

Let's go."

Scotty looked at him curiously. "Where are the caps?"

Rick patted his pockets one at a time. "One in each breast pocket and one in my watch pocket. Don't push me around, buddy. I'm loaded."

Scotty grinned. "I'll keep my distance."

The rest of the party was loading jeeps now, too. Scotty hoisted the equipment and lunches into the back of the jeep and got in with them.

Rick climbed gingerly into the front pa.s.senger seat and Zircon got ready to drive. He handed Rick a map. "You navigate. Our first destination is marked with a cross. We start out on the road leading west from the hotel. That will take us to the pumice works."

"Okay," Rick began, but he never finished. The jeep began to rock under him. For an insane instant he thought it must have a perfectly silent motor, then he realized Zircon had not yet turned on the ignition switch. Sudden dizziness made him clutch at the seat, and instinctively he clapped an arm across his chest to protect the dynamite caps.

He was vaguely conscious of yells from around him, and he struggled to sit up straight. His stomach was churning and he felt nauseated. Zircon let out a bellow like a wounded steer.

From inside the hotel Rick heard the sudden crash of shattering gla.s.s and gripped the jeep seat tighter with his free hand.

Then, as suddenly as it had come, it was over. He straightened up, dizzy. "Wh-what happened?" he asked shakily.

He heard Dr. Balgos. "A warning, my friends. The most serious one yet."

He pointed up to where the peak of El Viejo loomed. "The Old One must be working faster than I thought."

"But what was it?" Rick asked again and at the same time was afraid that he knew.

"Earthquake," Zircon boomed. He pointed.

Rick stared. In a zigzag line across the hotel parking lot was a fissure, one that hadn't been there a minute before. The concrete gaped in widths varying from a crack to a few inches.

The earth had opened up!

CHAPTER III

Firing Parties

It was a shaken group of scientists that moved off in their jeeps to the preselected stations. Most of the adults had experienced earthquakes before, but none had seen the earth split almost at their feet. To Rick, the sensation had been as upsetting as any he had ever experienced.

"The one thing we learn to depend on," Zircon said, "is that the earth under our feet is solid and dependable. When it shakes like a jelly, it causes a kind of emotional shock, apart from any physical damage it may do."

"It certainly did with me," Rick agreed.

"Ditto," Scotty added.

Zircon put the jeep in gear and moved away from the hotel. He drove slowly over the narrow part of the crack in the parking lot, then picked up speed. Rick looked around. Bradley Connel and Ruiz were following in their own vehicle.

Zircon took a blacktop road to the west, close to the base of the mountain. Fortunately for Rick's peace of mind, the road was fairly smooth. He had never carried dynamite caps before, but he knew they contained fulminate of mercury, which is one of the most unstable and violent chemical substances, pound for pound, ever created.

The big scientist sensed his uneasiness. "Relax, Rick. Those caps won't go off without a substantial knock against something. Enjoy the scenery."

Rick grinned. "I'll try."

The scenery was tropical. Once away from the hotel grounds, there was heavy growth, vines, creepers, and broad-leafed plants. He saw palmetto and wild banana interspersed with Judas palms and other typical vegetation. The growth clung to the side of El Viejo like a thick green carpet. Now and then the jeep pa.s.sed an open s.p.a.ce in the vegetation and he saw the plains stretching away to the sea on his left.

The jeep climbed gradually and Rick realized that their direction had changed. They were now heading on the more northerly course. The vegetation was thinner, too, and he guessed it was because they were higher up the mountainside. At a rough estimate, the jeep had climbed nearly a thousand feet.

"Pumice quarry ahead," Zircon announced.

Rick saw ramshackle wooden buildings, then piles of grayish rock. A hundred yards farther on he saw an open pit. This was where the San Luzians mined pumice for export.

"Is there much of a market for it?" Scotty asked.

"Not as much as there was years ago," Zircon replied. "Pumice, as you probably know, is volcanic rock. But not an ordinary one. It's a kind of foamy lava honeycombed with gas bubbles. It's used as an abrasive.

Modern industrial products have replaced it in general use, but apparently there's still enough demand so that the San Luzians are able to export a little. Our firing station is about a mile from here."

Rick looked at the rough terrain. "Think we can get through?"

"Easily. According to the map, we have an unpaved road part of the way."

The unpaved road turned out to be a pair of wagon tracks. But at least there were no trees in the way. Rick held on tight as Zircon shifted into four-wheel drive and forged ahead.