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 Cox, 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 analyzer 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 pronto," 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 snatches, 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."
 
"What about them Brungarian sidewinders?" put in Chow.
 
"That's the question!" Tom swooped down to rejoin the other two craft. "We'll keep an eye out for enemy blips while we do our prospecting."
 
Rather than lose time trying to contact Bud, Tom decided to let him find the Sea Hound. Accordingly, he switched off the antidetection s............