THE Tracy brothers were gathered inside Module 4 looking at the damage on Thunderbird 4.

Alan let out a whistle. "Brains is sure gonna be mad at you when he sees that," he said teasingly.

"Knock it off, will you?" retorted Gordon. "You think I take pleasure in what I did? I had to do it. I had to be sure Scott and Virgil got everyone out safely."

"There are better ways, Gordon," said Scott, whose anger towards his brother had dropped significantly following the talkdown by Virgil. "But, thank you. And I'm sorry for shouting at you."

Gordon nodded. "Thanks, Scott. I may have already said it, but I'm sorry too."

Scott broke a smile and patted his brother on the shoulder.

"So…why have we landed in this field on a Spanish clifftop?" asked Alan as they all walked out of the module. In front of them stood the vastness of the Atlantic Ocean. "The rescue is done. Surely we need to get back to base?"

"John asked us to come here," Virgil said. "He didn't say why but I'm sure he has his reasons."

Scott's radio then bleeped. "Speak of the devil," he said. "Go ahead, John?"

John's hologram appeared on Scott's wrist-controller. "Guys, I've just been in conversation with Admiral Hart at the navy base. He's asked if we can stick around until the Valiant comes in."

"The Valiant?" said Gordon. "Why does that name sound familiar?"

"That's the British navy's flagship Aircraft Carrier if I'm not mistaken?" said Virgil.

"That's right," said John. "She's on her way to Gibraltar to take part in the navy day and onward deployment in the Mediterranean. Turns out the crew you recovered from the water raided the submarine and found an orders document from the Bereznik lead sub. It specifically stated that it and the other two missing subs are going to try and sink it and its task force."

"That would explain why the destroyer took off in such a hurry," said Scott. "Where is the Valiant right now, John?"

"About twenty miles from the Strait of Gibraltar. It has an escort of eight destroyers and frigates," John said. " Let's hope that's enough to fend off the Berezniks."

"The Berezniks are a stubborn bunch," Gordon said. "I remember we had one working with us at W.A.S.P. Tried to flirt with several of the ladies - including my old partner Hayley."

"What happened to him?" asked Alan.

"Got thrown out in the end," said Gordon. "Commander Shore takes no prisoners when it comes to strict discipline. But the guy tried to sneak back in until he was eventually deported. I wouldn't be surprised if they attack the escorts in order to get to the carrier."

"Which is exactly why we need to be on stand-by," said John. "If the escorts fail to locate and disable the subs - we might be their only chance of rescue."

"Understood," said Scott. "We'll remain on stand-by until the ships safely arrive at Gibraltar."

"F-A-B," said John. "I'll be monitoring them constantly and will inform you of any developments."

Virgil looked out to sea. For some reason he was still thinking about the young woman he'd pulled from the water. I hope she's safe, he thought to himself. Wish I could have seen her properly.


Twenty miles from the Strait of Gibraltar came the large Queen Elizabeth-class Aircraft Carrier HMS Valiant. Surrounding her were her escorts. Leading the formation were the frigates HMS Devon, Lancashire and Fife sailing level at line abreast. Behind the Lancashire was the Valiant and behind her was the Royal Fleet Auxiliary refuelling ship RFA Neptune and the fourth frigate HMS Northumberland bringing up the rear. Behind the Devon on the left flank guarding the Valiant and Neptune's port-side were two of the Dragonfly's fellow destroyers - HMS Daunting and Dedalus whilst behind the Fife covering the carrier and resupply ship's starboard-side were HMS Dominator and Dastardly. It was a tightly-formed group with the carrier having regular aircraft flying over the formation to cover.

On the bridge of the Valiant was Admiral Anthony Marshall. He had been informed by Admiral Hart of the danger of the rogue Bereznik submarines and had ordered all ships to Action-Stations. But as he gazed out of one of the windows, he couldn't help feeling a little worried.

"Mr Reay?"

Captain Christian Reay came over. "Yes, sir?"

"How's the weather looking?" asked Admiral Marshall.

"Not too good, I'm afraid," replied Captain Reay. "Some strong winds and potentially pitching waves. I know we aren't too far from the Strait but-"

"Still enough time for the Berezniks to strike," said Admiral Marshall. "And we can't launch planes in this weather."

Captain Reay got called away for a second then returned. "Some good news, Admiral. We've got an extra destroyer joining us. The Dragonfly. She's going to scout around for the subs ahead of us."

"That's some comfort," said Admiral Marshall. "But I'll feel a lot better knowing that the subs have either failed or have been dealt with."


As the wind picked up, the sea began to swell, causing both the carrier group and the Dragonfly to bob up and down in the water. For those on the Dragonfly, this was totally different to the warm, smooth climate and waters of the Mediterranean where they'd been only a few hours beforehand.

The cheerful mood that had been on the ship first thing that morning was also long gone. Ever since the discovery of the Andromeda's lifeboat the mood had become uneasy. Since the attack of the B-926 against the Queen Alexandra it had become tense. The subsequent attack on the Liparus and the self-destruction of the C-850 causing the deaths of Fitzgerald, Brace and Banner had made everyone angry and determined to hunt down the remaining submarines and bring their reign of hidden terror to an end.

With rain beginning to fall, Hayley was now inside. Dr Hebb had declared that despite being shaken by the ordeal she was physically fine. Captain Hart wanted her to rest but Hayley wished to remain on the bridge as she found rest impossible to manage right now.

As she stood at the rear of the bridge, propped up against the wall, Fallowfield entered with a single mug of coffee. "Doctor asked me to bring this to you, ma'am," she said, passing it to Hayley.

Hayley took it gratefully. "Thanks, Millie," she said as Fallowfield then left again.

Captain Hart came over to her. "Hayley, I know you probably want to see these subs stopped more than any of us, but I would rather you be resting."

Hayley took a sip of the coffee. "Unless you're ordering me to, sir, I'm staying right here," she said. "I won't get in the way. I promise."

Captain Hart gave a small smile. "I had a feeling you would say that," he remarked as he headed away.

Hayley moved over to the radar and sonar scope where Taylor was looking fed-up. She could see the contacts of the Valiant and its escorts off to starboard, but apart from that, both scopes showed nothing.

Taylor had been listening to the sonar through some headphones. She let out a deep sigh and lifted one off so she could rub a finger in her left ear.

"Getting annoyed with constant pings?" Hayley asked.

Taylor rolled her eyes. "How could you tell?" she replied. "I've had these damn things on for most of the day. I'm going to end up in a mental asylum after hearing sonar all through my head for the rest of my life!"

Hayley, feeling the need to help, saw her chance. "Would you like a break?" she asked. "I could have a listen for you."

The two young women looked over at Captain Hart who nodded his approval. Taylor removed the headphones and gave them to Hayley. "Thanks," she said gratefully. "I'm gonna see the doctor about some cream for my ears, sir." She then left the bridge.

Hayley put the headphones on and began to listen. Every few seconds the sonar probe in the bow of the Dragonfly sent out a pulse. It was a single repetitive noise as it wasn't bouncing off any potential targets. As she settled back to listen, there was still something bugging her. Something in the World Aquanaut Security Patrol that she'd learned about the Bereznik submarines, and yet she could not quite place it.

Willis was having a slightly difficult time trying to keep the Dragonfly on course for the wind was buffeting the ship and causing it to deviate from the direction it was meant to be going in. "These waves are a bit troublesome, sir," he said to Captain Hart.

"Do your best, Mr Willis," Captain Hart replied. "She's a tough old girl. She'll get us through."

"How do you reckon our chances with finding the subs?" asked Friend.

Captain Hart shrugged. "Honestly cannot say," he said. "Those things are practically impossible to detect. They must have some kind of silencer or special kind of propulsion."

"Like the Russian Typhoons did?" said Friend.

Captain Hart nodded. "Exactly like that," he said. "Caterpillar I believe they called it."

Hayley's eyes shot up. She only had one of the headphones on and had overheard what Captain Hart had just said. The word 'caterpillar' sounded very familiar. She thought back to her training in the W.A.S.P. One of the tasks was to try and hunt down the rogue vessels and the instructors had even said about the special kind of propulsion that some of them used having adapted old Russian technology. Was it possible, Hayley pondered, that these submarines had the same kind of silent propulsion as well as their sonar-absorbing outer skin which made them virtually impossible to detect?

Hayley closed her eyes and removed the headphones for a second. She'd been made to listen for a specific sound that the caterpillar system made. Although it was very quiet, it wasn't totally silent and only a very trained ear would be able to identify it. She took a few moments to try and remember what it sounded like before putting the headphones back on and adjusted the sonar to listen acoustically rather than sending out pulses. Turning the underwater microphone manually, she quickly identified the distant sounds of the Aircraft Carrier and its escorts. And then she found it. It was very faint, but she could hear a noise very similar to the one she'd heard in class at the W.A.S.P. It sounded like a very faint heart beating rapidly. She adjusted the sonar to get a compass reading. The destroyer was heading on a course of Two-Zero-Zero. The beating sound was ten degrees to the left but gradually moving along to cross their path.

"Sir? I think we might have something," Hayley said.

Captain Hart, Friend and Willis all looked over at her. "We do?" asked Captain Hart.

"Yes!" said Hayley, with a tad of excitement in her voice. "I heard what you said about caterpillars and I suddenly remembered that I had a lecture at W.A.S.P. about the special noise that the caterpillars make and how to detect it. And I do believe that I've found one."

"Where?" asked Captain Hart.

"Judging by this - a bearing of One-Nine-Eight. Range - 3,000 yards."

Captain Hart looked at the scope. "Why isn't it showing?"

"Because I've adjusted it to listen acoustically," said Hayley. "These can't be detected by our modern scan sonar, but they can be by acoustic."

Captain Hart was amazed and impressed. "Can you guide us to him?" he asked.

Hayley broke into a grin. "Captain, it would be my genuine pleasure," she said.

Captain Hart quickly drew up a plan. He grabbed the tannoy microphone. "Attention all hands - this is the Captain speaking. Lieutenant Madison may have just located one of the subs. She's going to guide us in and we will see if it is friend or foe. Everyone be on your guard. AA crews prepare to take any surface to air missiles should the enemy launch them. Depth-charge crews be ready to drop if ordered to. It's unlikely we'll be able to make a torpedo attack so they may be our best hope. God bless you all - and good luck." He replaced the tannoy speaker and called down to Langford in the communication room. "Langford?"

"Aye, sir?"

"Contact Admirals Marshall and Hart. tell them we have a possible target. Request back-up if the Valiant can spare it."

"Sir!" said Langford and immediately set about making the calls.


Captain Reay received the message on the bridge of the Valiant and handed it to Admiral Marshall. "Dragonfly looks to have found one of them, sir," he said. "They've requested back-up if we can spare any of our escorts?"

Admiral Marshall thought carefully before making his decision. "Granted," he said. "Tell Lancashire and Northumberland to break from the formation and to go rendezvous with Dragonfly. Our flanks will remain protected."

"Aye-aye, sir!"

Captain Reay quickly relayed the orders to the lead and trailing frigates. With blasts from their sirens, the two small ships broke off from the rest of the formation and proceeded at full speed to the position of the Dragonfly.


Concealed beneath the surface, the B-925 was slowly closing in on its target - the Valiant. Using its powerful sonar, the crew were steering a course to intercept the Task Force.

"About thirty minutes and we will be in range, Duìzhǎng," said the Sonar-Operator.

"Excellent," replied the Commander. He then turned to his Weapons Officer. "Have all torpedoes and missiles prepped and ready for launch."

"Da, Duìzhǎng," said the Weapons Officer.

It was then that the Sonar-Operator then picked up another signal - one that puzzled her. "Duìzhǎng?"

"Da?"

"There appears to be ship heading our way," said the Sonar-Operator. "Going by size and speed, I would say it's destroyer."

The Commander looked at the sonar screen at the contact. "Probably just coincidence," he remarked. "Maintain course."

A few minutes went by with the Sonar-Operator closely monitoring the approaching vessel. "Ship has altered course, Duìzhǎng," she said. "It seems to be adjusting according to our position."

The Commander looked at the screen again. "Strange," he said. "Periscope depth!"

"Glubina periskopa!" ordered the Executive Officer.

The B-925 had been sailing at two-hundred feet below the surface. It rose up to fifty feet and was now at its periscope depth. The Commander pressed a button and the periscope rose up into position. He then looked through the periscope and turned it around. The visibility was poor, but he could just make out the shape of a warship coming in their direction. He lowered the periscope again.

"You think they can hear us, Duìzhǎng?" asked the Executive Officer.

The Commander shook his head. "Nyet, Kloup-Sing," he said. "I suspect it's coincidence."

"Duìzhǎng, with respect I suggest we find out for sure," said the Executive Officer. "Make two turns and see if ship reacts to it."

The Commander thought for a moment, then nodded. "Very well. Give instruction."

The XO turned to the helm-station. "Gǎngkǒu èrshí dù."

The B-925 began to make a twenty degree turn to the left.


Captain Hart, Friend and Taylor, who had returned to the bridge, watched Hayley with anticipation as she gave them regular updates. With the adjustment of the sonar-scope, Hayley had been able to set it up to show any acoustic sound waves as little flashing dots on the screen. "Slight increase on the starboard caterpillar," she said.

"What does that mean?" asked Taylor.

"It means they use the caterpillar thrust to change course," Hayley replied. "It'd say they're turning to port."

"Then they must have detected us and are trying to test our response," said Friend.

"Then let's not show him that we are," said Captain Hart. "Maintain course."

"Aye, sir!" called Willis.

"What's his range?" Captain Hart asked Hayley.

"2,300 yards. He's directly ahead of us," Hayley replied.

"Once he gets within 2,000 yards we can use a Hedgehog on him," said Friend.

Captain Hart nodded. "Have them stand by for directions, Chris," he said.

Friend hurried to the microphone. "First Officer to Hedgehog Battery. Prepare to engage submarine. Stand-by for directions."

This made Seward and Parr rather excitable. "Oooooooh!" exclaimed Seward. "We actually get to do something!"


The B-925's Commander, XO and Sonar-Operator watched the contact.

"There is no change to their course, Xiānshēng," said the Sonar-Operator.

"Make course change," the Commander said to the XO.

"Yòuxián sìshí dù," ordered the XO.

The submarine began to turn again. This time it was a forty degree turn to starboard.


"They're turning again," Hayley said. "To starboard. I estimate forty degrees."

"Course change, sir?" asked Willis.

"Negative," replied Captain Hart. "We alter our course now he'll realise we're tracking him. Let's make him think that we're not. At least not until it's too late for them to do anything."


The silence inside the B-925 was almost too much to bear. For several years its crew had remained hidden from the world and they were used to travelling with the understanding that nothing would ever find them. They were also unaware of the fate of the B-926 and that it had failed in its own assignment.

"Any change?" asked the Commander.

"Nyet, Duìzhǎng," said the Sonar-Operator. "They continue on their course."

"Should we attack?" asked the XO.

"Nyet," said the Commander. "If we do that then Carrier group will know of our presence. Our orders are to shadow group until A-850 and B-928 are in position. Then we attack together. Resume course."


Hayley continued to monitor the submarine's progress. "Changing course again," she said. "Going back onto what they were originally on."

"Then we're nearly ready to engage them," said Captain Hart. "Range?"

"2,180," said Hayley.

"Very close," said Taylor.

"Tell Hedgehog mount to raise the elevation to forty-five degrees," Captain Hart said to Friend. "Hayley, as soon as we're level with him on our starboard bow, give the order to turn. Then when we're lined up, he's ours."

Friend nodded and relayed the instructions to the weapon crew.


For the next few minutes the Dragonfly and the B-925 continued on their respective courses. Most of the submarine's crew had relaxed, back with the belief they weren't detectable. The Sonar-Operator however continued to watch the scope and was still a bit worried about the destroyer that was about to pass behind them around 2,000 yards away. Then her attention was grabbed by something else. Whilst she'd been busy looking at the ship in close proximity, she'd failed to notice that two ships had broken away from the Valiant's group and were now heading in their general direction. Her eyes widened when she saw the two contacts that were the Northumberland and Lancashire heading their way. "Duìzhǎng?"

"Da? What is it?"

"Two ships from Carrier group are coming this way…" said the Sonar-Operator.

The Commander looked at the screen again and frowned. "What?" he said. "Why would they be coming towards us?"

"Perhaps they're going to join the destroyer in trying to hunt us and our comrades?" suggested the XO.


Seward and Parr were ready with the Hedgehog launcher. It had been raised to the correct position and they were eager to press the launch button.

Hayley and Taylor watched the sonar screen, their eyes barely blinking for the concentration was very strong. "2,000 yards!" Hayley said. "Direct abeam starboard."

Captain Hart exhaled. "Here we go then," he said. "HARD A-STARBOARD!"

Willis spun the wheel around and the destroyer made a very sharp turn to the right, the whole vessel leaned as it went with the spin. The attack was on.