"We figured Bud and Mel could make out on their own," Zimby explained. "And we thought the sub's course or actions might tip us off to its nationality. Also, if it tried any sabotage or mine-planting, we could radio the Navy."
Instead, Cox went on, the mysterious craft had proceeded to a point about ten miles offshore where it rendezvoused with another submarine.
"And get this, skipper!" Mack Avery put in. "The other sub was undetectable! We were close enough to get a peek at it, but we couldn't ping it on the sonarscope."
"That figures," Tom said grimly. "Those frogmen were apparently Brungarians."
Zimby Cox related that a man had transferred from the undetectable submarine to the one they had been following. The first sub had then headed out to sea, as if to cross the ocean back to its home base. The other had departed on a course toward the South Atlantic.
"Probably back to the lost missile area. At least that's the way we figured it," Zimby added.
"And neither sub spotted you?" Tom questioned.
Zimby grinned wryly. "We might not be here if they had detected us. But I'm pretty sure they didn't. Anyhow, they gave no sign."
Tom was doubly elated at the news. His antidetection gear had evidently worked perfectly in a showdown test with the enemy, even at close range. Moreover, if the second sub was returning to the South Atlantic, it seemed likely that the enemy, too, had not yet located the precious missile with its data from Jupiter.
"You guys rate Navy medals," Tom told Zimby and Mack jubilantly. "Come on back to Shopton with me and I'll buy you the juiciest steaks in town!"