The prisoner was wearing a frogman costume and a mask which hid the lower part of his face. The man's dark eyes glittered in hate, as Tom ordered him to remove his mask. Sullenly the prisoner obeyed.

Tom gasped. "_Dimitri Mirov!_" The name sent a shock through the Americans aboard.

"Wal, I'll be jing-whistled!" Chow declared, then broke into a gleeful cackle.

Under their scornful gaze, the Brungarian's own eyes wavered and his shoulders slumped in an att.i.tude of defeat. "What is the use?" he muttered. "Again I have failed. My career is over now, just like my brother's."

Tom seized the opening. "In that case, maybe you're ready to do some talking now."

Mirov shrugged. "What do you wish to know?"

In answer to Tom's questions, Mirov admitted that his group, composed of Brungarian rebel Navy men and rocket engineers, had sabotaged the returning Jupiter probe missile, hoping to obtain its data for their own use.

Their key agent in America was the man who had posed over the phone as Lester Morris and masterminded the other attempts to kidnap Tom. He had also taken the amulet bracelet from Ames's jacket in a restaurant.

Mirov himself had been given the bracelet after his jail break. Pulling back the sleeve of his frogman suit, he displayed it with a momentary smirk of pride.

"I even got inside the grounds of Swift Enterprises and stole a plane that same night," Mirov boasted.

Tom was startled. "How did you manage that?"

"Very simple. I thumbed a ride with one of your trusted workers on the late shift and showed him the amulet to identify myself as a Swift employee. The guard at the gate was fooled the same way."

Tom nodded thoughtfully. "They were instructed to look for a man trying to sneak past alone. Seeing you in the same car with a known employee, he probably a.s.sumed you were all right."

Mirov was allowed to change into dry clothes, then his hands were bound behind his back. When the water cleared, Tom and Bud ventured outside again. First they headed for Bud's jetmarine to rea.s.sure his crew. Here they learned that the mystery submarine had vanished.

"Good riddance!" Bud exclaimed jubilantly. "They probably didn't even realize you had found the missile!"

"_Had found_ is right--past tense," Tom said wryly. "It's no doubt buried again. But at least we have the right spot."

They emerged from the jetmarine and headed back toward the site. As they glided astern of the _Sea Hound_, Tom uttered a cry over his suit mike.

"_Bud! There it is!_"

Both boys darted ahead at increased speed, and Tom played his flashlight beam over the precious treasure. Instead of burying the missile deeper, the grenade explosion had uncovered the entire nose cone and part of the section behind it!

"Sizzlin' squids! What a break!" Bud whooped.

The boys jetted back to the _Sea Hound_ to announce the good news. Zimby and two other crewmen were dispatched in hydrolungs to inform the other ships. Tom requested them to remain submerged and guard the site.

Twenty minutes later the _Sea Hound_ was zooming up to the surface. Tom hoisted the craft's aerial and radioed word to his father, who was overjoyed. Mr. Swift, in turn, had news--that the rebels' key man and Len Unger had been seized by the FBI. Tom's next call was to Admiral Walter.

"Tom, this is wonderful news!" the admiral exclaimed. "I'll have our Navy ships routed back there immediately--and I intend to fly out myself as soon as I can board a plane!"

As Tom waited for the task force to arrive, his thoughts turned to new inventions to tackle. But he could not antic.i.p.ate what would happen to him in his _Triphibian Atomicar_.

Within hours, the task force arrived at the site and recovery operations got under way. The missile was hoisted to the surface by cables attached to submarines, then hauled aboard the tender. Tom himself supervised the job of extracting the sealed data section.

"You've done a tremendous job, Tom Swift, and our whole country will be proud of you!" Admiral Walter declared before sailing home.

Tom grinned as he prepared to descend the ladder over the side. "Let me know about life on Jupiter, sir. I may go there myself one of these days!"