Tom, Bud and Mr. Swift braced themselves for a plunge into the black frigid water. Then, just as they were about to slip over the edge of the floor panel, it tilted upward and the yawning gap closed. The three lay in a heap, breathing heavily and trying to calm their nerves.
       Tom gulped. "Boy," he said, "we nearly had a deep-sea bath!"
       Bud managed a grin. "But what would we have down for hot water? Complain to the management?"
       Mr. Swift looked grave. "Captain, don't you think you owe us an explanation?"
       "I reversed the switch," Roccula replied, "because this was only a demonstration. But we do mean business. You'll follow my orders from now on, or I'll dump you in the sea."
       "What kind of orders?" Tom asked?
       "Orders regarding the mastodon. I'm responsible for getting the best out of the ocean. It's a delicate job, and you three have the know-how, so you're going to help me."
       "Very flattering," Tom murmured.
       "Not at all. Everybody has heard of the Swift reputation. I intend to cash in on it."
       "Why should we place our scientific knowledge at your disposal?" Mr. Swift inquired.
       Roccula flushed angrily. "First, because you'll have a one-way trip if you refuse. And second," he added craftily, "because I just might release you after we've finished the job."
       The three prisoners were not fooled by that implied promise, but they had no choice.
       "After all," Tom said, "the mastodon must be preserved. Brungaria may not be friendly to the U.S., but I'd rather have this relic of the Ice Age on display in enemy territory than in pieces at the bottom of the ocean."
       Mr. Swift nodded in agreement. "We can't let the science of paleontology down."
       Roccula smiled and rubbed his hands triumphantly. "I thought you'd see it my way," he crowed. "Now, come into my quarters."
       After motioning the three prisoners into seats around his desk, the commander gave a rapid outline of the Brungarian plan.
       "You can feel that this sub has started to move," he began. "We have the mastodon in tow."
       "In tow?" Bud asked puzzled.
       "We're using the artificial vortex," Roccula explained. "The suction power is low enough to keep the mastodon from being swept into the holding chamber. We could tow it back to Brungaria, but our scientists are afraid the block of ice might disintegrate in transit. So we're heading for a secluded bay on the coast of Chile."
       He pointed to a spot on the map south of Santiago near the city of Lula. Tom made a mental note of the location. On a nearby chart he saw the rocky channel at the entrance to the bay.
       A Brungarian freighter is anchored there," Roccula went on. "It has a refrigerated hold big enough for the mastodon. We'll use hoisting gear to get the prehistoric elephant aboard. Come along."
       He led them through a corridor to an observation bay at the stern of the sub. Through a large porthole they could see the giant creature floating in the suction stream.
       "Now I've seen everything," Bud said.
       Tom did not reply. He had glimpsed a familiar outline in the water to one side. The seacopter! The next moment it had vanished into the murky depths. The Brungarians were so preoccupied with the mastodon, they didn't know they were being shadowed.
       "Ted saw them capture us," Tom thought. "I'd better keep Roccula and his men from spotting him." Aloud, Tom said, "Captain, will you show us the artificial vortex? I'm curious about it."
       Roccula looked pleased at the interest in his newest equipment. He took his three prisoners to the control room and explained how the invention worked.
       "One twist of the dial to the right turns on the full power," he said. "By the way," the Brungarian went on, "did you know we've constructed a receiving tank like yours?"
       "I might have guessed it," Mr. Swift retorted, "after your spies stole the plans from the university."
       Roccula smirked. "Ours is on display in the lobby of the Brungarian Capitol Building. It can collect anything a Transmittaton sends our way. Of course it's not made of Tomasite, and the transmitter still has our scientists baffled. But they will achieve a breakthrough. We'll have a Transmittaton better than yours!"
       "Maybe," Bud said with a grin, "but I wouldn't count on it."
       The commander scowled. Without another word he turned away and began to work intently on some charts. Several hours went by as Tom concentrated on their predicament and formed a plan.
       Suddenly the sub's motors were cut off. "We've moved through the rocky channel," the captain said.
       The craft came to a halt in the deep, wide basin of the bay. Grappling lines descended through the water from the freighter above.
       While Roccula was busy giving orders, Tom whispered to Bud and his father, quickly outlining a ruse he had in mind.
       Tom had just finished when Roccula came toward the. "Get into your suits again," he ordered. "Join my men outside. They're ready to attach the cables to the mastodon."
       Mr. Swift glanced knowingly at his son, then slumped to the floor with a loud groan of pain.
       "What's wrong?" Roccula snarled.
       "Dad's having another attack of appendicitis!" Tom gasped. "We must do something!"
       "Forget him," Roccula snapped. "You two––outside! And don't try any stunts. You're outnumbered.!"
       Tom and Bud donned their Fat Man suits. They went outside, where the enormous chunk of ice containing the mastodon lay on the floor of the Pacific. It had dropped gently into the silt when the vortex power had been turned off.
       Brungarians in diving suits were already at work. Some guided cables through the water; others were busy handling the big clamps and hooks that would lift the block to the surface.
       The captain came outside to give directions. "How does it look to you, Swift?" he asked over his sonar phone.
       "Okay, Captain, except we need more hands on the job. Guiding the mastodon up through the water will be the hardest part. We should have every last man from your crew out here helping to balance the block of ice."
       The Brungarian commander eyed Tom suspiciously. "I'm counting on this team to carry out the assignment."
       "You could be making a big mistake," Tom insisted. "This mastodon is so heavy, these men couldn't possibly keep it from crashing to the bottom in pieces if the hooks slip."
       A scowl revealed that Roccula was weighing Tom's advice. His confidence seemed to be slipping.
       "I wonder how you'll explain it back in Brungaria," the young inventor went on, "if you should lose the mastodon. And after your government provided their latest sub with all that shiny new equipment––including the artificial vortex."
       The captain shuddered. The idea of explaining the loss to his superiors obviously did not appeal to him. The Brungarians were known to have unpleasant methods of dealing with those who failed to carry out orders.
       "You may or may not be correct," Roccula told Tom, "but I can't afford to take any chances. I'll give you all the men you need. And you'd better make a success of this operation!"
       He commanded the rest of the crew to come outside except for one man who was left on duty to guard the sub. The others emerged in divers' suits, and their commander assigned them to positions around the block of ice.
       In the midst of all this confusion Tom stepped aside, switched off the light in his Fat Man suit, and turned on his sonar pen. Ted Brice's voice came in a moment later, reporting he had the seacopter lying underwater just outside the bay.
       "Where's the Sky Queen?" Tom asked.
       "She's still circling over the place where the mastodon fell into the water."
       "Okay, Ted. Tell the radioman to contact both the lab at the Castilla hacienda and the university on the West Coast. We're about to deliver the goods. Cliff Culbertson is to train the Transmittaton on the mastodon in this bay, and trigger the machine. Timing––exactly a half hour from now."
       "Roger," the pilot answered. "I'll surface behind the headland we passed coming in. that way I'll be able to send the radio message without interference."
       After snapping off the sonar pen, Tom lighted his Fat Man suit again and rejoined the group. No one had noticed his absence. Through the intercom he gave Bud a quick report on his talk with Ted Brice.
       "Let's go!" Bud called out to the Brungarians. "We want this brute on the surface."
       Clamps were tightened around the top of the ice, and hooks fastened to the clamps. The cables became taut as the freighter began to roll them in. Ponderously the mastodon was lifted from the silt.
       Tom gave orders to the men guiding the massive creature in its icy prison. Carefully he controlled the speed at which the animal was hauled up. Captain Roccula kept a sharp eye on Tom.
       Slowly the mastodon rose toward the surface. Members of the crew trailed behind, each gripping the lower rim of the ice. Finally the chunk broke the surface. The taut cables strained to bring their burden clear out of the water, and started to haul it up the side of the ship.
       One by one the members of the crew appeared on the surface and bobbed up and down like corks. Bud, Tom, and Roccula were among them. They watched the hoisting operation intently.
       Tom looked at his chronometer. The job had taken exactly half an hour. But, he wondered, had Ted Brice relayed his message? Was the Transmittaton ready for action?
       As he asked himself these questions, Tom saw the answer. One moment the dripping column of ice swung from the cables alongside the Brungarian vessel; the, without warning, the whole thing vanished––ice, mastodon, grapples!
       "Dive, Bud!" Tom shouted into the intercom. "Make for the sub!"
       Their Fat Man suits took the boys to the bottom in a rapid descent. The Brungarians came after them, wild with baffled rage.
       Hitting the bottom with ihs pantograph feet, Tom pulled Bud against the sub and rapped hard on the hull. Beyond them, the artificial vortex snapped on in a swirl of water.
       "Dad got my message!" Tom said.
       The Brungarians, swimming furiously after their prey, zoomed without thinking into the path of the powerful suction current. The man in the lead was whirled headlong into the holding chamber of the sub. The net man followed him, then the next, until every one had been snapped up by the vortex.
       Roccula came last. As the suction hurled the captain into the chamber on top of his men, the hatch closed automatically. At that moment Mr. Swift joined the boys in a Fat Man suit.
       The Chilean Navy will be interested in these Brungarians," he stated, and told of having knocked out the crewman who had been left on board to guard him.
       "You scheme has worked so far, Tom," Bud commented. "What gives now?"
       "I told Ted Brice to meet us with the seacopter. And here he comes right on time."
       "Welcome aboard!" Ted greeted the three as they got in with him. "I'm glad you came through that okay."
       "We're thankful you knew we were in a spot," Tom answered. "I've never seen a more beautiful sight than the seacopter trailing that Brungarian sub."
       Ted surfaced and flew back to the Sky Queen. The entire crew cheered as the Swifts, Bud, and Ted emerged from the seacopter into the hangar. The excited greetings were interrupted by the radioman who handed Tom a message from the West Coast university. Tom read it aloud:
       "'Have received one mastodon on ice in perfect condition! Congratulations!'" A second cheer broke out.
       "Bud chortled. "I'd like to see the Tall One's face when he hears that."
       It did not seem long to the boys before the Sky Queen landed once again in the valley near the Castilla hacienda. Chow and the lab technicians were waiting. Most of the equipment had been packed. Only the Transmittaton remained at the lab.
       "Bud and I will pick it up," Tom said. "We're going to the hacienda to say good-by to Señor Castilla."
       The orange grower thanked the boys for their splendid help. "Everything is back to normal," he said. "The villagers are happy to be working again without fear of the Snowman or blue fire. And the Chilean police have rounded up those Brungarian spies at the estancia on the strait."
       He led Tom and Bud to the underground lab. In it was the Brungarian Melt Master! "I had this brought down from the mountain," Castilla explained. "Now it is like a white elephant on my hands. I have no idea what to do with the machine. I wish the Brungarians had never brought this invention to Chile."
       "I think I can take that problem off your hands, Señor Castilla," Tom said with a twinkle in his eye.
       He picked up a brush. Then, in large black letters, he painted on a piece of cardboard: OUT OF ORDER. Tom hung the sign on the front of the Melt Master.
       The next moment he activated the Transmittaton. In a flash the Brungarian machine disappeared.
       "Where did it go?" Castilla blinked his eyes in astonishment.
       The young inventor replied with a broad grin, "The famous Melt Master has just been transmitted to the receiving tank on display in the Capitol Building of Brungaria!"