Night Probe!

There were few creature comforts for the three-man crew. Humans were essential only for emergency operation or repairs. The craft was automatically operated and piloted by the computer brain center at NUMA headquarters in Washington, almost three thousand miles away.
"How about a little medicine to clear the cobwebs?"
Pitt lifted his head and looked into the mournful bloodhound eyes of Sam Quayle, the electronics wizard of the expedition. Quayle held up a pair of plastic cups and a half pint of brandy, whose remaining contents hardly coated the floor of the bottle.
"For shame," said Pitt, unable to suppress a grin. "You know NUMA regulations forbid alcohol on board research vessels."
"Don't look at me," Quayle replied with mock innocence. "I found this work of the devil, or what's left of it, in my bunk. Must have been forgotten by an itinerant construction worker."
"That's odd," said Pitt.
Quayle looked at him questioningly. "How so?"
"The coincidence." Pitt reached under his pillow and pulled out a fifth of Bell's Scotch and held it up. The interior was half full. "An itinerant construction worker left one in my bunk too."
Quayle smiled and handed the cups to Pitt. "If it's all the same to you, I'll save mine for snakebite."
Pitt poured and handed a cup to Quayle. Then he sat back on the bunk and spoke slowly: "What do you make of it, Sam?"
"Our evasive caller?"
"The same," answered Pitt. "What's stopping him from dropping in and giving us the once-over? Why the cat-and mouse game?"
Quayle took a healthy belt of the Scotch and shrugged. "The Doodlebug's configuration probably won't complete on the sub's detection system. The skipper is no doubt contacting his command headquarters for a rundown on underwater craft in his patrol area before he pulls us over to the curb and cites us for trespassing." Quayle finished his drink and gazed longingly at the bottle. "Mind if I have seconds?"
"Help yourself."
Quayle poured himself a generous shot. "I'd feel much safer if we could pin a name tag on those guys.,"
"They won't come within range of our scan. What beats me is how they can walk such a fine line. They seem to dip in and out as if they were taunting us."
"No miracle," said Quayle, making a face as the Scotch seared his throat. "Their transducers are measuring our probes. They know within a few meters of where our signals die out."
Pitt sat up, his eyes narrowed. "Suppose…... just suppose?"
He didn't finish. He left his quarters at a half run, clawing his way up the ladder to the control room. Quayle took another swallow and followed. Only he didn't run. "Any change?" Pitt asked.
Lasky shook his head. "The uninvited are still playing cagey."
"Gradually fade the probes. Maybe we can draw them closer. When they step into our yard, hit them with every sensing device we've got."
"You expect to sucker a nuclear sub, manned by a first-rate professional crew, with a kindergarten trick like that?" Quayle asked incredulously.
"Why not?" Pitt grinned fiendishly. "I'll bet my snake medicine against yours they'll fall for it."
Quayle looked like a salesman who had just sold a waterfront lot in the Gobi Desert. "You're on."
For the next hour it was business as usual. The men went about their chores of monitoring the instruments and checking the equipment. At last Pitt looked at his watch and gestured in Lasky's direction. "Systems standby," he directed. "Ready systems," Lasky acknowledged. "Okay, nail the bastard!"
The data unit in front of them burst into life and the remote display swept across the screen.
Contact: 3480 meters.
Course: Bearing one zero eight.
Speed: Ten knots.
"He bit the hook!" Quayle couldn't keep the excitement out of his voice. "We've got him!"
Overall length: 76 meters.
Beam (approximate): 10.7 meters.
Probable submerged displacement: 3650 tons.
Power: One water-cooled nuclear reactor.
Design: Hunter-killer.
Class: Amberjack.
Flag: U.S.A.
"It's one of ours," Lasky said with obvious relief "At least we're among friends," Quayle muttered. Pitt's eyes were intent. "We're not out of the woods yet."
"Our snoopy friend has altered his course to zero seven six. Speed increasing," Lasky read aloud from the screen. "He's moving away from us now."
"If I didn't know better," Quayle said thoughtfully, "I'd say he was setting for an attack."
Pitt looked at him. "Explain."
"Several years ago, I was a member of a design team that developed underwater weapons systems for the navy. I came to learn that a hunter-killer sub will come to flank speed and break away from the target prior to a torpedo launch."
"Kind of like firing your six-shooter over a shoulder at the villain while riding out of town at full gallop."
"A fair parallel," Quayle allowed. "The modern torpedo is crammed with ultrasonic, heat and magnetic sensors. Once fired, it goes after a target with ungodly tenacity. If it misses on the first pass, it circles around and keeps trying until it makes contact. That's why the mother sub, figuring the target has weapons of the same capability, gets off the mark early and takes evasive action."
A concerned look came over Pitt's face. "How far to the bottom?"
"Two hundred and thirty meters," Lasky answered.
The metric system had never quite caught on with Pitt. Out of habit he converted the reading to about 750 feet. "And the contour?"
"Looks rough. Rock outcroppings, some fifteen meters high.
Pitt walked over to a small plotting table and studied a chart of the seafloor. Then he said, "Switch us on override and take us down."
Lasky looked at him questioningly. "NUMA control won't take kindly to us cutting off their reins."
"We're here, Washington is three thousand miles away. I think it best if we command the vessel until we know what we're facing."
Confusion showed in Quayle's face. "You don't seriously think we're going to be attacked?"
"As long as there's a one percent probability I'm not about to ignore it." Pitt nodded at Lasky. "Take us down. Let's hope we can get lost in the seafloor geology."
"I'll need sonar to avoid striking an outcropping."
"Keep it locked on the sub," Pitt ordered. "Use the lights and TV monitors. We'll eyeball it."
"This is insane," said Quayle.
"If we were hugging the coast of Siberia do you think the Russians would hesitate to boot us where it hurts?"
"Holy mother of Christ!" Lasky gasped.
Pitt and Quayle froze, their eyes suddenly taking on the fear of the hunted as they stared at the green letters glowing on the display screen.
Emergency: CRITICAL.
New contact: Bearing one nine three.
Speed: Seventy knots.
Status: Collision imminent.
Time to contact: One minute, eleven seconds.
"They've gone and done it," Lasky whispered with the look of a man who had seen his tomb. "They've fired a torpedo at us."
Giordino could almost smell the foreboding, and he could see it in the eyes of Dr. King and Admiral Sandecker as he burst through the door of the computer room.
Neither man acknowledged his arrival or so much as glanced in the direction of the swarthy little Italian. Their full concentration was fixed on the huge electronic display covering one wall. Giordino quickly scanned and absorbed the readout on the impending disaster. "Reverse their forward motion," he said calmly.