A cold chill ran down Tom's spine. Could the ghosts be planet-hopping toward earth? "From Saturn to Jupiter is a big step in our direction," he thought, hanging up the phone. "Now we have only Mars between them and us!"
       He consulted his father, who agreed to get in touch with their secret contact in Washington. Tom, though deeply disturbed by Ames's information, felt his personal promise to retrieve the mastodon for the United States government should not be broken. He joined Bud. The boys hastened to Tom's room, where they packed for their trip to Chile. Although Bud did not live at the Swifts' home, he always kept some clothes there.
       The girls looked on from the doorway. "How come you're going off by yourselves?" Sandy asked.
       "You never take us any more," Phyl chimed in.
       Tom and Bud looked at each other sheepishly. "Okay, Girls, we agree," Tom said. "But this time it's legit. We must go alone."
       Bud added, "But we'll take you out soon."
       The two youths drove to Swift Enterprises in Bud's red convertible, spent the night in Tom's private suite adjoining his lab, and rose before dawn. A familiar voice greeted them as they entered the small dining room.
       "Wal, I'll be a horned toad, if it ain't my old buddies back on this here range! What kin I do for you broncobusters?"
       Tom grinned. "How about some of your choicest cement biscuits, Chow?"
       "And a little of that coffee-stained water you perk," Bud kidded.
       Charles "Chow" Winkler was a former chuckwagon cook from the Texas Panhandle. He had met the Swifts while they were doing atomic research in the Lone Star State, and they had persuaded him to come North with them. A pudgy, balding, bowlegged, happy-go-lucky character, Chow was the Swifts' private chef at Enterprises and frequently went on scientific expeditions with them.
       "Boys, them would be fightin' words where I come from," he answered, "but I cain't reach for my six-gun when there's a mess o' hawg on the fire."
       Bud gulped. "At this time of the morning?"
       "Yup! It's my new system––making use o' leftovers. You varmints have a try before turnin' up your noses."
       After sampling Chow's fare, Tom confessed, "Not bad." Bud agreed. Between them, the boys ate everything the cook served.
       Dawn was breaking when Tom and Bud boarded a small jet for their flight to Santiago, Chile. When the boys landed outside the city that afternoon, they were met by their contact, a sturdy suntanned man, wearing a white suit and Panama hat.
       "I'm John Burkart," he introduced himself. "Estate manager for Fernando Castilla. He is one of Chile's leading orange growers. You will stay at his hacienda."
       The boys crowded into the front seat of his car, and Burkart drove about a hundred miles from the airport to the foothills of the Andes.
       "What a magnificent spot!" Tom exclaimed.
       Snow-capped mountains rose above the Spanish type, one-story villa. Behind the house lay a group of low, tile-roofed outbuildings including a stable and garage.
       The owner of the estate greeted them affably. Fernando Castilla was tall and distinguished-looking. A heavy black beard covered half his ruddy face. He said that two Chillean engineers were staying at the hacienda.
       "They came to inspect the mastodon cave, but the Indians won't let them get near it. I hope you Norteamericanos can find the snowman and solve the mystery of the blue fire!"
       "Where is the cave, Señor Castilla?" Tom asked.
       "I do not know."
       "Nor do I," Burkart said. "The local people won't tell us. However, the Indian who discovered the cave has volunteered to show us the way. His name is Juan Alvarez. He's waiting for us in the village. Shall we drive there at once?"
       "Let's go!" Bud urged.
       With Burkart driving, the soon reached a large cluster of adobe dwellings. Burkart parked the car under a tree and led the way down a narrow muddy road to a small house with a red-tiled roof. He knocked several times, but thee was no response. Burkart went inside but soon returned.
       "Alvarez has disappeared!" he exclaimed.
       "Maybe there's the explanation," Tom suggested with suppressed excitement. He pointed to giant footprints in the mud, leading up to the house. Another set of prints led away from the house toward the mountains.
       "You mean," said Bud, "that Alvarez may have been kidnapped by the snowman?"
       By now a group of terrified neighbors had gathered at the Alvarez home. They jabbered excitedly in Spanish.
       "We heard him scream during the night!" one declared.
       "The giant came and took him!" a second cried in a trembling voice. "The snowman––last survivor of a race of giants who inhabited this land in ancient times!"
       The rest of the villagers chorused their fears in loud tones. They showed by their scowls that they would not let the mountain spirits be offended any more.
       "Nothing to be learned here," Burkart commented in a low voice. "Let's go back to the hacienda before we get into trouble."
       The two Chilean engineers came in just before eight o'clock. They were introduced as Señor Querido and Señor Venegas. The two had spent the day searching for the mastodon cave. The result was complete failure. Both looked grave when they heard the news of Juan Alvarez's disappearance.
       "We must try to find him, said Señor Castilla. "I hope he is still alive." During dinner their host briefed the boys on the background of the mastodon mystery.
       "When word got out that the prehistoric elephant had been found by and Indian hunting mountain sheep, the Chilean government received a bid for it from another country."
       "Brungaria?" Tom inquired.
       "My young friend, you have guessed correctly," the orange grower replied. "But the Brungarians did not offer a fair price. Hence the decision of my country to sell to the United States."
       Castilla looked thoughtful. "I do not believe the Brungarians were sincere in their offer. They wanted to find out where the mastodon was and prevent the Americans from having it.
       "Could they be behind the strange blue fire in the mountains?" Bud wondered.
       "And the giant snowman?" Tom added.
       "Very likely," their host replied. "When they learned that the Indians had discovered the cave, they devised a method to frighten them away. The Brungarians probably sent the snowman to kidnap Alvarez when they learned he was about to show you the cave."
       Tom mulled over this. "Of course," he pointed out, "the Brungarians may have found the cave themselves. So not only would they want to stop us from getting it, but they may be planning to steal the mastadon!"
       The others around the table stared at the young inventor incredulously, and Castilla asked, "But how?"
       "I know the Brungarians," Tom continued. "They'll stop at nothing! They wouldn't hesitate to melt the ice just to get the mastadon!"
       "But that could trigger an avalanche!" Castilla shuddered. "Imagine a river of ice rolling over our village at the foot of the mountain! Such a catastrophe must be prevented! But how?"
       "We'll get there first!" Bud declared.
       "And find the cave and remove the mastodon safely," Tom stated.
       As Tom and Bud were preparing for bed, a servant knocked on their door and said the young inventor was wanted in the radio room. Castilla, a ham radio enthusiast, maintained a station that could pick up messages from around the world. The call was from Swift Enterprises. Castilla handed Tom a slip of paper with the message:
       Ghosts now on Mars! Come home tomorrow for consultation.
       Tom returned to the bedroom and showed the message to Bud.
       "Ghosts on Mars! A mastodon in an unknown cave! What a combo, Tom!"
       "The situation is becoming desperate, Bud! The Photo-Essence is closing in on earth! They're practically on our doorstep!"
       "Isn't there something we can do?" Bud asked.
       "I'll have to find some way of communicating with these invaders," Tom explained. "I still don't know what they're made of. Are they intelligent?"
       Bud climbed into bed. "They might be a threat to us whether they're intelligent or not. Look at what happened to our space friends on Uranus," he observed as he turned off the light.
       Tom nodded. "They could be dangerous to life on earth. Bud, I can't sit by and let the P-E move in! Humanity might be wiped out!"
       "That thought gives me nightmares!" his pal admitted. "I agree we must do something to head them off!"
       Bud went to sleep, but Tom returned to Señor Castilla and asked to send a message to Mr. Swift. He requested that his father try contacting the ghosts with the same symbols he used for his space friends.
       By morning he had an answer: No sign that the ghosts understood us.
       "I'll think up something else," Tom decided.
       Señor Castilla was in a highly nervous state. "I slept hardly any last night," he said. "And this morning an official of the Chilean government phoned from Santiago. He said that the men in our intelligence bureau are so worried, they're asking your help to get to the bottom of these frightening events around here."
       Burkart spoke up. "The Alvarez family is pinning its faith on your ability to find Juan. They feel that perhaps the famous Norteamericanos can bring him home safely."
       "I, too, beg you," Castilla continued. "My orange-growing business is being harmed. Workers aren't showing up. I am most upset because the people of the village are so disturbed. I hope you can dispel their fears!"
       "We'll do our best, Señor Castilla," Tom promised. "There has to be an explanation for everything that has happened."
       "Right now," said Bud, "it looks like a jigsaw puzzle, but don't worry, señor. Tom Swift is the world's number one expert to fit the pieces together!"
       Tom modestly denied this. Then he announced that the boys must return home. "But we'll be back soon."
       Burkart drove Tom and Bud to Santiago. He dropped them in the heart of the city instead of the airport because Tom and Bud wanted to sample some typical Chilean cooking. They found a table at an outdoor restaurant and soon were eating the specialities of the house.
       "This was worth a flight to South America," Tom remarked, opening a succulent shellfish with the twist of a knife.
       "You said it," Bud agreed after sampling a luscious Chilean fruit salad.
       An Indian in a sombrero, with a bright-colored manta draped across one shoulder, walked from his table toward the exit. He jostled their table with his elbow in passing.
       "What's––?" Bud began.
       "Look!" Tom interrupted him, pointing.
       On the table lay a beautiful crimson flower, its petals forming a delicate cup. It gleamed in the sunlight. Tom and Bud recognized the copihue blossom, Chile's national flower, which they had seen growing luxuriantly by the side of the roads and in the mountains.
       This one had a note fastened to its long stem. Tom detached the paper and flattened it on the table. Two words were written on it. Tom read them aloud:
       "Alvarez––Valdivia!"
       "Who, or what is Valdivia?" Bud asked.
       "We'd better ask our messenger!" Tom replied.
       They quickly paid the bill and hurried from the restaurant. They were just in time to see the Indian disappear into a crowd down the street. He was walking toward one of the busy boulevards of Santiago.
       "We can head him off!" Tom said, dashing forward. Bud followed.
       They elbowed their way past pedestrians, straining their eyes to keep the man in sight. As the boys stepped off a curb into the traffic, they heard a blare of horns, screams, and warning shouts.
       A speeding car was barreling directly at them!