As Tom emerged from the tank, the portly cook rolled up his own pantlegs and waddled up the metal ladder to the tank brim. He summoned the porpoise with a whistle and straddled its back.

"What in the name of aquanautics do you think _you're_ doing?" Tom gasped.

"I'll show you a real broncobustin' act in the water," Chow bragged.

Smiley glided off gently at first, Chow fanning the air with his hat and yipping like a rodeo star. He did, in fact, cling to his slippery perch with considerable skill.

But suddenly Smiley began bobbing and humping like an eel. Chow's face froze in alarm. A moment later the porpoise dived and the cook let out a yell of terror, "He-e-elp!"

Roaring with laughter, Tom dived in and rescued him. "Guess he ain't quite broke yet, pardner!"

"Reckon not."

Now that Tom had all his technical problems solved, he plunged eagerly into the job of fitting out his expedition to the South Atlantic to search for the lost Jupiter missile.

[Ill.u.s.tration]

Besides the _Sea Hound_ and the other diving seacopter which had already been rigged with antisonar and antidetection equipment, Tom ordered a large cargo jetmarine to be similarly equipped.

[Ill.u.s.tration]

Then he drew up a list of supplies and underwater search gear needed for the missile hunt. Tom phoned orders to a dozen different departments. Food, s.p.a.ce-plant pills, extra clothing, tools, including a midget atomic earth blaster, grappling hooks--nothing was overlooked.

"I'd better take along a Damonscope too," Tom reflected. "Judging by those Navy reports, ordinary Geiger counters haven't revealed anything."

Tom's Damonscope, one of his early inventions, was a photographic device which worked on fluorescent principles. It was amazingly sensitive to any form of radioactivity--and the missile, of course, would be "hot"

from exposure to cosmic rays.

Meanwhile, Tom had ordered his new hydrolung suit, with its four-plunger control unit and porpoise sonar, to be flown back to Enterprises. Arv Hanson had promised to make up several duplicates with a team of technicians working on all-night shifts.

Late the next afternoon Tom returned to the mainland to confer with his father. Mr. Swift reviewed the expedition plans with approval.

"Suppose we call Admiral Walter now and set a time for the Navy to move out of the missile area, so you can take over," his father said.

Tom agreed, and his father placed the long-distance call to Washington.

Moments later, Admiral Walter came on the line. Mr. Swift talked to him briefly, then turned the phone over to Tom, who described his preparations for the missile hunt. A time schedule of operations and communications was quickly laid out.

The admiral was amazed to learn that Bud Barclay was already patrolling the area. "Our ships haven't seen or heard him!" the officer exclaimed.

Suddenly Admiral Walter broke off. "Hold it, please, Tom! A code call is just coming in!"

His voice was grave as he returned to the Swifts' line. "That message was from your friend, Bud Barclay," Admiral Walter reported. "It looks as if our enemy has found the missile!"

"Oh, no!" Tom groaned.

CHAPTER XIX

FLASH FROM THE DEPTHS

Tom was stunned by the news. "There's no chance of a mistake?"

"Judge for yourself," Admiral Walter replied. He read the message:

HAVE JUST SIGHTED ENEMY CRAFT DREDGING OUT METAL OBJECT

Tom repeated the information to his father. Both Swifts were silent for a moment, exchanging dejected looks. Then Mr. Swift remarked evenly:

"The game's never lost till it's over, son."

"You're right, Dad!" Tom exclaimed. Turning back to the telephone, he said, "Admiral, I'm not quitting. We'll take off as soon as I can get back to the base!"

With a hasty good-by to his father, and farewells to his mother, Sandy, and Phyl by phone, Tom dashed out of the building. He sped to Arv Hanson's workshop, and the new hydrolung suits were loaded onto a small pickup truck and taken to the airfield. While flying back to Fearing Island in a helijet, Tom received a radio flash from his father.

"Another message from Bud. He says the object dug up by the Brungarians was _not_ the missile. It appeared to be the metal section of a ship's prow, from some hulk buried in the silt!"

Tom was jubilant. "Terrific news, Dad! Our luck may be turning!"

At the rocket base Tom detailed crews for the three undersea craft which were to take off on the expedition. Arv Hanson would captain one seacopter, Mel Flagler the jetmarine, while Zimby c.o.x, Chow, and four crewmen would accompany Tom in the _Sea Hound_.

Because of their sonar-blinding systems, Tom realized there was a chance of the ships losing contact with one another--especially if their a.n.a.lyzer sonars developed trouble. He therefore plotted their course to the South Atlantic carefully, and issued orders for the antidetection circuits to be switched off every half-hour for a position check.

"Report to your ships," he now ordered.

As Tom was about to leave base headquarters, Harlan Ames telephoned from Shopton. "Bad news, Tom. Dimitri Mirov has broken jail!"

"Good night!" Tom stifled a groan of dismay. "How did it happen?"

Ames said the Brungarian had somehow fashioned a crude weapon and overpowered the turnkey. Disguising himself in the guard's uniform, he had slipped out before his victim was discovered.

"He must have had outside help within close call," Ames ended, "because he seems to have made a clean getaway. The State Police have spread a dragnet, but it doesn't look hopeful."

"He'll probably duck out of the country p.r.o.nto," Tom surmised. "Anyhow, this won't stop us, Harlan."

By nightfall the little fleet of three undersea craft was speeding southward at periscope depth. Tom alternated at the controls with Zimby, two hours on and two hours off. Sleep came in s.n.a.t.c.hes, the crewmen flopping on their bunks as the chance offered. Chow's tasty meals helped break the monotony.

It was the following day when they reached the missile search area. Tom surfaced the _Sea Hound_ and reversed blade pitch, then gunned the rotor turbines for an aerial reconnaissance flight, while the jetmarine and the other seacopter stood by in the water.

"Brand my guppies, it's some ocean, eh, boss?" Chow remarked in an awed voice.

"Big enough, all right," Tom agreed with a grin. "And plenty of water to search in."

"No sign of the Navy," Zimby said.

Tom nodded. "They pulled out on schedule."