As they reached the rocks on the end of the beach, Tommy saw a zodiac with a single driver bouncing across the waves towards where Schweindeiner was standing. They crouched behind one to observe. "They're picking him up."

Barbara grunted. "Why the hell didn't he just go with the boxes and save us a hike?"

"Then we wouldn't have this scenery as our last memories."

"If we're blown to kingdom come, how will we remember?"

"I'm trying to be positive, Barbara."

She grunted again. "The red boat still has a way to go. I don't suppose you have a spare bazooka?"

"No, I knew there was something I forgot to pack."

"Pity, me too. Hey, is that a Russian badge on the sub?"

Tommy squinted to see the red hammer and sickle on the side of the conning tower. "Not Russian exactly. That's Soviet."

"The difference being?"

"After USSR collapsed, they sold off a lot of military equipment to private individuals, submarines included. I assume this is one of them. The Russian government uses different insignia."

"Will the satellite see it?"

"I imagine they will even know the model and maker. They might be able to trace who bought it."

The boat ran up onto the sand. As Schweindeiner went to climb aboard, two figures ran down the beach towards him. One was pointing a pistol at him.

"Who the hell is that?" Barbara asked.

"Kati and Volker."

"What are they...?" A shot rang out followed by a volley of machine gun fire. "Who's shooting?"

"Volker shot at Schweindeiner I think, and the boat driver must have an automatic weapon. Stay here and call it in."

Tommy stood and ran towards the beach. He was unsure what he was going to do, but hiding behind a rock was insufficient. He had to do something. He dived behind another rocky outcrop when the boat driver spotted him and lifted his weapon. Splinters of rock rained down on his back. Another three shots came from the beach. Tommy saw Schweindeiner fall backwards. He lay on the sand grasping his knee and shouting curses in German. Kati was shouting back as she knelt over Volker who was prostrate on the sand. As he got closer he could see the boat driver floating face down in the water. A pool of red swirled around him.

"Kati?" Tommy called, "is Volker alright?"

"Nein, nein. Er stirbt. He is dying."

Tommy ran to the couple. Volker had a row of small holes in his jumper in a line across his chest. Laboured shallow wheezes burbled with blood. "I'm so sorry. Why are you here?"

"We are Bundesnachrichtendienst. We came to stop him poisoning the world."

"BND? Barbara and I, we are..."

"Ja, British Metropolitan Police. We know. Only the British would send bobbies as spies. We were monitoring you." Her eyes moved off Tommy. "Careful!"

Sensing movement behind him, Tommy turned just as Schweindeiner lunged for Volker's gun. Tommy was faster. His hand wrapped around the handle and raised it in one fluid motion. "Don't even think about it." The man made another lurch forward. Without conscious thought, Tommy shot him in the other leg. The German screamed then rolled into the foetal position clasping his knees.

Volker's hand grabbed Tommy's coat. "Must... stop... the... boxes. Help Kati."

"We will, I promise."

"Ja... gut." Volker's hand opened and fell away. His eyes glazed and after one last gasping wheeze, his head lolled to the side.

Tommy closed his eyes. "I'm sorry."

Kati shrugged. "He was my colleague, nothing more."

Tommy did not believe her but was not going to question it. "Even so, I know how it feels to lose someone close."

Barbara raced along the beach. "Tommy, the red boat is nearly at the sub." She looked at Volker and turned to Kati. "I'm so sorry, Kati."

Kati waved her hand. "Take the rib," Kati ordered. "Stop them."

Tommy turned and for the first time noticed that the blood on Kati's jeans was hers, not Volker's. "You're wounded."

"I'll live. It entered above my knee, and I think it passed out my buttock. I can guard Schweindeiner. You must stop them loading those boxes."

Tommy looked at Barbara. They both leapt up and sprinted to the rib. Tommy pushed it off the sand then scrambled over the side. "Hang on," he told Barbara as he started the engine.

"Cameron said to ignore the spores. The Danish Navy SEALS raided the research station. They are Arctic Mushrooms spores and harmless. The lab thought they were providing them for a commercial breeding programme."

"Okay, good." The boat bounced over a large waved drenching them in water. "Sorry."

Barbara leant closer so she could be heard. "They also raided Schweindeiner's lab. The stuff is a powder, but it is rendered harmless if it comes into contact with salt water. If we can tip it in without breathing any of it..."

"If we sink the box we should be okay. We could try to sink the boat."

"No, what if the sub can recover it. We have to destroy it, Tommy."

"Easier said than done."

Barbara nodded. "I know. Look, the red boat is nearly at the sub. Can you get between them?"

"I'll try. Get up the front. This is going to get rough."

By his reckoning, it was almost a kilometre to the boat. Even though they looked closer, there was a couple of kilometres between the red boat and the sub. Tommy steered the zodiac straight at the delivery vessel. Behind it, a large iceberg loomed. The smooth white face silhouetted the red in a strikingly beautiful contrast. On the deck, he could see movement. Apart from the captain, two men were on the rear deck next to the boxes. One had a short-barrelled automatic rifle but seemed uninterested in their approach.

"They must think we're Schweindeiner," Barbara shouted at him over the noise of the outboard.

"Good, we need all the time we can get." Tommy noticed the barrel of an Uzi wedged between the inflatable side and the aluminium deck. "Barbara, can you reach that weapon? Be careful. It's probably not on safety. I think the driver dropped it."

Holding on to the rope running along the top of the rib, Barbara reached under and tugged the gun free. She quickly flicked on the safety catch and cleared the weapon. "The mag is half full."

Tommy bumped the boat over the wake of the red boat. "That'll have to do."

Barbara leant down. "There's a box of magazines here. All full."

Tommy smiled. "Then we have a chance."

A loud crack ricocheted across the bay. Their boat jerked violently. Both turned fearing gunfire but then saw a zagged vertical line in the iceberg behind the red boat which was bobbing like a cork as the captain fought for control. "The berg cracked," Barbara said. She sounded awestruck. "Look, part of it fell off."

"Pity it didn't turn..." Tommy had an idea. "Barbara, if I swing the boat around. Empty the mag into the base of the crack."

"You're mad. We'd have to get underneath it."

Tommy turned the rib and sped towards the wall of ice. It was groaning and crackling. He could almost feel the energy waiting to explode. He pushed the outboard to the left, and the boat began to turn. "Now!"

He watched as the Uzi jumped in Barbara's hand. She gripped it harder and aimed at the spot he wanted. Large shards of ice broke away. The Uzi went silent. Barbara ejected the empty mag and expertly jammed in another and continued to shoot. The rib bobbed violently in the wake of falling ice.

"Enough." Tommy gunned the engine. He leant forward as if urging it to go faster. The top of the berg began to lean towards them.

"Hurry!"

"It's going flat out."

For the next thirty seconds, Tommy was sure that they would be crushed by a wall of falling ice. The noise was deafening as the ice swivelled and fractured. Large chunks fell into the sea around them. He glanced back to see the red boat slowly being dragged towards the berg.

He smiled as he looked at Barbara. "Its engines aren't big enough to outrun it."

She looked over her shoulder and swore. "They're throwing the boxes overboard."

"They'll be crushed by the ice."

"They look like they're floating to me."

Tommy knew if they turned back they would die. He hesitated before revving the engine back to full. "We'll go back after the berg breaks."

Barbara nodded then pointed up ahead. "Who's in that zodiac?"

"No idea. Danish SEALS with any luck."

"They normally send more than one person."

Further speculation ended with a sudden eerie silence. They turned to look just as the berg rolled on top of the red boat. Seconds later Tommy's ears rang as the thunderous splintering explosion reached them. The concussive wave threw them back into the boat. The engine died when the force pulled the kill switch from around his wrist. Tommy instinctively rolled to cover Barbara as chunks of ice hit them. He grunted as a searing pain burned in his shoulder.

"Tommy? Are you, okay?"

They struggled to sit up as the rib corkscrewed in the high waves. Water washed over the side. On his knees, Tommy crawled towards the outboard. Grateful that it had an electronic starter, he reinserted the kill key and pushed Start. The engine sputtered but did not fire. He cursed as he opened the choke and repeatedly pressed the button. It took almost a dozen attempts before it roared to life. Tommy spun the boat around and headed back into the wake, the safest way to manage the dangerously high waves.

"You're hurt."

"No, I'm okay."

"Tommy, there's blood coming out of your neck."

He felt his neck. A warm ooze coated his fingers. He felt around. The wound was at the top of his shoulder away from his carotid. The large lump over his collarbone explained the pain. "I'll live. It's not too bad. I think I've cracked my clavicle. Where's the boat?"

"I can't see it."

A claxon horn sounded twice. Tommy glanced towards the sub as it slowly sank from sight. "The sub's diving. Hang on tight."

"Why?"

"Just hang on, Barbara."

Within seconds, her question was answered. As the sub dived, they were sucked towards it at frightening speed. The ocean turned into a washing machine as their zodiac dipped, rose and tumbled. Tommy gripped the handle of the outboard with both hands as he fought for control. Barbara wrapped her legs around him and twisted the rope around her arms three or four times. For what seemed like an hour, Tommy was sure they would die.

"I love you," he shouted. A grunt was his only answer.