The last time she had seen him was at her grandfather's funeral. He never forgot her birthday, and sent her a card with money in it every year until she graduated from college. She didn't know the details of the bond between Schroeder and her family, but she knew from hearing the story many times that when she was born her grandfather had persuaded her parents to name her after the mysterious uncle.

"I don't know how you found me in this remote spot," Karla said.

"It wasn't hard. The university told me where you were. Getting here was the difficult part. I hired a fishing boat to bring me in.

When I didn't see anyone at your camp, I followed your trail. The next time you go off on an expedition, please make it closer. I'm getting too old for this kind of thing." He cocked his ear. "Hush."

They sat in the silent darkness, listening. They heard muffled voices, and the scrape of boots against rocks and gravel at the mouth of the cave. Then the darkness was leavened by a yellowish light as the bushes blocking the entrance were moved aside.

"Hey in there," a man's voice called in Russian.

Schroeder squeezed Karla's hand in a signal to be silent. It was an unnecessary gesture, because she was nearly frozen with fear.

"We know you're in there," the voice said. "We can see where someone cut the bushes. It's not polite not to answer when people are talking to you."

Schroeder crawled forward a few yards, where he had a view of the cave's mouth.

"It's not polite to kill innocent people, either."

"You killed my man. My friend was innocent."

"Your friend was stupid and deserved to die," Schroeder said.

Hoarse male laughter greeted his answer.

"Hey, tough guy, my name is Grisha. Who the hell are you?"

"I'm your worst nightmare come true."

"I heard someone say that in an American movie," the voice said. "You're an old man. What do you want with a young girl? I'll make a deal. I'll let you go if you give us the girl."

"I heard someone say that in a movie too," Schroeder said. "Do you think I'm stupid? Let's talk some more. Tell me why you want to kill the girl."

"We don't want to kill her. She's worth a lot of money to us."

"Then you won't harm her?"

"No, no. Like I said, she's worth more as a hostage."

Schroeder paused as if he were seriously considering the offer.

"I have lots of money too. I can give it to you right away and you won't have to wait. How does a million dollars American sound?"

There was a whispered discussion, then the Russian came back. "My men say it's okay, but they want to see the money first."

"All right. Come closer to the cave and I'll throw it out to you."

The conversation had been in Russian and Karla had understood only part of it. Schroeder whispered to Karla to move deeper into the cave and to cover her ears. He reached into his pack and pulled out an object that looked like a small metal pineapple. He knew that his offer would draw the attackers in like jackals, and, with any luck, he could take out all of them. He stood up. Shards of pain shot up his right leg. The run and climb while carrying the young woman had aggravated the ankle injury.

He moved closer to the entrance. He could see shadows moving closer. Good. There was a slight bend in the cave, and the entrance was a narrow slit, so his aim and timing would have to be just right.

"Here's your money," he said, and pulled the pin from the hand grenade.

As he stepped forward to toss it out of the hole, his injured right leg buckled and he fell, slamming his head against the wall of the cave. He almost blacked out. As his eyes were closing, he saw the grenade hit the ground and roll to a stop only a few feet away. He pulled himself back to consciousness and forced himself to hang on. He lunged for the grenade, felt the hard metal in his hand and again tossed it to the entrance.

His aim was better this time, but the grenade glanced off the wall and came to rest in the dead center of the opening.

Schroeder threw himself deeper into the cave and around the bend, where he gained the shelter of the wall. He clamped his hands over his ears just as the grenade exploded. There was a flash of light and a burst of white-hot metal as the shrapnel peppered the cave in a deadly fusillade. Then came a secondary roar as the entrance collapsed.

The cave was filled with dust. Schroeder lifted his head up and crawled toward the sound of coughing. The light flashed on, but the beam was diffused by the brown curtain of dust that hung in the air.

"What happened?" Karla said after the dust settled.

Schroeder groaned and spit out a mouthful of dirt. "I told you I'm getting too old for this sort of thing. I was about to toss out the grenade when I tripped and banged my head. Wait." He took the flashlight and made his way to the entrance. He came back after a minute and said, "I did a good job. We can't get out, but they can't get in."

"I don't know about that," Karla said. "The leader of those men said they have a portable jackhammer."

Schroeder considered her comment. "We'll have to go farther into the cave."

"This place could go on underground for miles! We could become hopelessly lost."

"Yes, I know. We will only go as far as we need to set up an ambush. I will try not to be so clumsy next time."

Karla wondered if she was talking to the same man who had bounced her on his knee so many years ago. He had cleanly dispatched the man who tried to rape her, calmly negotiated with a band of murderers, and then, in a businesslike fashion, tried to kill the gang.

"All right," she said. "But this secret you mentioned. What do you know about it?"

Karl fished a candle out of his pack, lit the wick and stuck it onto a ledge using melted wax.

"I met your grandfather for the first time near the end of World War Two. He was a brilliant and courageous man. Many years ago, he came upon a scientific principle that, if used unwisely, could cause great death and destruction. He wrote a paper warning of the possibilities, and the result was not what he expected. The Nazis captured him and forced him to work on a superweapon, using his theories."

"That's incredible. He never gave any hint that he was anything but an inventor and businessman."

"It's true. However, I helped him escape from the lab. He had refused to give up his secrets, and his stubbornness cost him his family. Yes, that's right. He was married and had a child before he moved to the United States after World War Two. He took his secret to the grave, but these men, or the ones they work for, think he passed the secret on to you."

"What makes them think I know anything like that?"

"History repeats itself. You published an article on the extinction of the woolly mammoths."

"That's right. I said it was due to climate changes caused by a polar shift. I used some of my grandfather's papers and his calculations to back up my theory. Dear God! Is that what they want?"

"That and more. They will do anything and kill anyone to get it."

"But everything I know is in public view. I don't know anything about any secret!"

"Your grandfather told the Nazis the same thing. They didn't believe him either."

"What can I do?"

"For now, you can keep yourself well." He went back into his pack again and came out with some jerky and water. "Not exactly cordon bleu, but it will do for now. Maybe we will find some bats that we can cook into a big stew."