"Oh, yeah."  Jones flipped open his clipboard.  "Yesterday morning, night, whatever it was, after I got off watch, it started bothering me, so I used the move we made offshore as a baseline to do a little course track for him.  I know how, Skipper.  I read the manual.  It's easy, just like we used to do at Cal Tech to chart star motion.  I took an astronomy course in my freshman year."

Mancuso stifled a groan.  It was the first time he had ever heard this called easy, but on looking at Jones' figures and diagrams, it appeared that he had done it right.  "Go on."

Jones pulled a Hewlitt Packard scientific calculator from his pocket and what looked like a National Geographic map liberally coated with pencil marks and scribblings.  "You want to check my figures, sir?"

"We will, but I'll trust you for now.  What's the map?"

"Skipper, I know it's against the rules an' all, but I keep this as a personal record of the tracks the bad guys use.  It doesn't leave the boat, sir, honest.  I may be a little off, but all this translates to a course of about two-two-zero and a speed of ten knots.  And that aims him right at the entrance of Route One.  Okay?"

"Go on."  Mancuso had already figured that one.  Jonesy was on to something.

"Well, I couldn't sleep after that, so I skipped back to sonar and pulled the tape on the contact.  I had to run it through the computer a few times to filter out all the crap—sea sounds, the other subs, you know—then I rerecorded it at ten times normal speed."  He set his cassette recorder on the chart table.  "Listen to this, Skipper."

The tape was scratchy, but every few seconds there was a thrum.  Two minutes of listening seemed to indicate a regular interval of about five seconds.  By this time Lieutenant Mannion was looking over Thompson's shoulder, listening, and nodding speculatively.

"Skipper, that's gotta be a man-made sound.  It's just too regular for anything else.  At normal speed it didn't make much sense, but once I speeded it up, I had the sucker."

"Okay, Jonesy, finish it," Mancuso said.

"Captain, what you just heard was the acoustical signature of a Russian submarine.  He was heading for Route One, taking the inshore track off the Icelandic coast.  You can bet money on that, Skipper."

"Roger?"

"He sold me, Captain," Thompson replied.

Mancuso took another look at the course track, trying to figure an alternative.  There wasn't any.  "Me, too.  Roger, Jonesy makes sonarman first class today.  I want to see the paper work done by the turn of the next watch, along with a nice letter of commendation for my signature.  Ron," he poked the sonarman in the shoulder, "that's all right.  Damned well done!"

"Thanks, Skipper."  Jones' smile stretched from ear to ear.

"Pat, please call Lieutenant Butler to the attack center."