In the moment that Tegan believed would be the last of her life, she was aware of the heat from the sun and the sound of the shifting sands. She held Adric's and Nyssa's hands; their skin felt warm. She could hear both of them breathing shallowly. A sharp noise caused her to recoil. She wondered if she would feel the bullet enter her.

Unexpectedly, the noise continued. It was not the crack of a bullet firing; it was a grinding, mechanical sound.

Tegan opened her eyes. Adric and Nyssa had done the same.

"The TARDIS!" Adric cried.

Several yards away, the blue police box materialized on the sand. Modory and Durmon stared at the large object in astonishment, momentarily distracted from their intended acts.

Without another word, Adric, Nyssa, and Tegan ran for the TARDIS. The door was already open, and the Doctor stood beckoning them.

Their movements quickly pulled Modory from his brief reverie. "Don't let them get away!" he shouted to Durmon. Both men raised their guns.

"Duck!" shouted the Doctor as the men fired.

The three runners bent their shoulders and backs as bullets whizzed just above their heads. Nyssa reached the TARDIS first, and the Doctor pulled her inside. Tegan was close behind her.

"To the left!" the Doctor yelled, watching the angle of Modory's gun. Tegan swerved slightly as another bullet flashed by her head. She thought that she felt its heat near her cheek. But then the Doctor was clamping his hand around her wrist and tugging her into the sanctuary of the console room.

"Adric! Down!" the Time Lord shouted, falling to his own knees and reaching out for the boy as Durmon took aim.

Adric dropped to his belly and scrabbled forward across the sand the last few feet to the TARDIS. A bullet narrowly missed his leg as the Doctor pulled him inside.

"Shut the door!" the Doctor cried. A bullet bounced off of the interior wall.

Nyssa pulled the lever that closed the outer door.

The Doctor hurried to the console and depressed the new yellow button, saying, "Kappa-Prime, 1983." The console remained still and quiet.

"Hmm," muttered the Doctor, "perhaps it is in need of a slight modification."

With a shake of his head, he punched at several keys. In a moment the familiar sound of the TARDIS dematerializing greeted the ears of the four companions.

Tegan and Nyssa leaned against the wall, panting. Adric was struggling to sit up near the door. The Doctor bent toward the boy.

"Is everyone all right?" the Time Lord asked, his eyes sweeping over his young friends.

Nyssa nodded; Tegan muttered an affirmative response. Adric remained silent. The Doctor tilted the boy's face upward.

"Adric? Did you hurt your leg or arm again?" he asked with concern.

Adric's eyes rested on Nyssa and Tegan; he seemed momentarily unaware of the Doctor's presence.

"Adric?" the Doctor repeated.

"Yes?" Adric shook his head slightly then looked at the Doctor.

"Are you all right?" The Doctor had placed his hand lightly on the Alzarian's injured arm.

"I'll be fine," the young man replied.

The Doctor stood, offering a hand to Adric to help him rise.

"You need to stay off of your leg for a while," the Doctor said, already leading Adric toward the hallway.

Adric nodded. "Wait," he said, stopping. He turned back to the young women.

"Thank you," he said to them, his cheeks flushing mildly.

"Come on," the Doctor urged, leading him out of the room as Nyssa and Tegan watched.

"He's acting a bit strange," commented Nyssa.

Tegan stood wearily. "He'll be all right. But I need a shower and a big glass of water—maybe two." She followed the Doctor and Adric out into the hallway.

----------

Several hours later, the TARDIS shivered to rest near a huge, red mesa. Tegan gazed at the view screen, saying, "This looks like the place."

The Doctor moved from the console to stand by her side. "Good. Based upon the information you gave me about the landforms, sky, and moons, this planet was the one best fitting your description. Interestingly enough, it is also about the same distance as Earth is from Anahsti. This planet is called Anun-Usti."

"The name Anun-Usti reminds me a little of Anahsti. The two civilizations must be related."

"Most likely. My guess is that the original inhabitants came from Anahsti but were unable to return, so they settled here and eventually grew to several rather sizable communities."

Tegan nodded. "And that's the origin of the Anasazi, too?"

"I imagine so. One day perhaps we'll make a stop in Utah or Arizona to see if we can find a transport chamber among the ruins. Of course, if it is like the one here, functioning only one way, it wouldn't explain how the Anasazi disappeared. Perhaps the theories about climate change or migration are correct." He touched the lever that opened the door, then held out his hand. "Shall we?"

The TARDIS had materialized at the far edge of the mesa in which the village of Tlan-Arana lay. A short walk, less than a kilometer, would take the Doctor and Tegan back to the village. They stepped out into the warm twilight. The Doctor immediately looked up at the dusky lavender sky.

"Quite lovely," he commented as they began to walk.

"The village is very pretty, too. It's the live form of the ruins we saw, minus the elaborate characters—erythrocytes, you said they were?"

"Yes."

"I still don't really understand it. My blood, and Adric's and Adam's, was absorbed into the stone and then somehow allowed us to activate the transport chamber, right?"

The Time Lord nodded. "Rather like a retinal scan."

"What? You mean like from inside the eye?"

"Something like that. You'll understand what I mean in fifteen years or so."

Tegan shook her head. "Maybe. But how could the rock do that—create images of our blood cells then recognize them to activate the transport?"

"Nyssa and I believe that the rock is not really rock at all; it appears to contain some sort of organic matter capable of recognizing and replicating microscopic cells. This process seems to establish some vague psychic connection between the individual and the matter. I wish we'd been able to bring a sample of it back to the TARDIS, but I'm afraid Sergeant Modory's arrival put a stop to that."

"But what's the point of it all?"

"It seems to serve an expansion purpose; certain individuals are sent to other planets, where they eventually reproduce and form new societies. It's a rather intriguing method for spreading a civilization throughout the galaxy, don't you think?"

"I suppose so. But how were those people chosen? Surely not everyone went out to other planets."

"No, of course not. Obviously most of the inhabitants of the village remained there. Those transported may have done so inadvertently, as you, Adric, and Adam did. Or perhaps only those with certain characteristics inherent in their DNA were sent."

"I'm not sure I want to know why I got to go, if that's the case. But how does the transport chamber work?"

"I have some ideas about that, but perhaps I should tell you another time. It's rather technical."

Tegan stopped for a moment and turned to the Doctor. "And you think I wouldn't be able to understand it, right?"

The Doctor paused, too. "Not at all, Tegan. I'm finding you quite capable in many regards. But the explanation is somewhat lengthy, and we haven't sufficient time now."

Tegan frowned slightly. "In what regards?" she asked.

"What?"

"In what regards do you find me capable?"

The Doctor smiled. "You appear to be quite a skilled nurse; Adric told me that you took very good care of him, as well as finding a way to drug your captors. You were also able to take him across this desert, which I'm sure was no small feat, considering his injuries."

Tegan found her cheeks growing warm.

"And," added the Doctor, "your drawings of the erythrocytes were quite good."

"Thank you." She did not know what else to say.

They continued walking, Tegan feeling surprised, albeit pleased, by the Doctor's comments. However, there was a less positive subject that she felt needed to be addressed. She began to gather her thoughts so that she would be able to articulate them clearly and strongly when the time was right.

----------

Twilight had faded into darkness. Standing at the base of the ladder, holding a small lamp, the Doctor said, "Are you certain that you want to do this? They may try to keep us here, as they did with you and Adric before."

"I know," Tegan nodded, "but I really feel sorry for Adam. If there's any way that we can take him back to Earth, I want to do it."

"His life there has long ceased. I doubt that he has many family members or friends left—"

"But at least he'd be home."

The Doctor placed his hand on a high rung of the ladder. "I think that I should go first, in case there's any threat when we reach the top."

"All right."

He began to climb, Tegan following a few rungs below him. Soon they stood on the path around the ledge. Lights glowed inside the dwellings; the inhabitants appeared to be inside their homes dining. Quietly Tegan and the Doctor walked along the path toward Adam's dwelling at the far end of the village.

"This is odd," commented Tegan when they reached the house. "The door isn't barred anymore."

"Hmm." The Doctor pushed the door open, and they stepped inside.

The dwelling was dark and still. The Doctor adjusted the brightness of the lantern and held it up to illuminate the room. Adam lay upon his pallet, flat on his back.

"Adam!" Tegan said, kneeling next to the elderly man to give his shoulder a gentle shake. "Come on, Adam, it's Tegan. I've come to take you back to Earth."

The Doctor stood behind her, watching Adam for a moment. "Tegan," he said, resting his hand on her shoulder, "don't."

She looked up at him. "What?"

The Doctor bent to touch Adam's chest. "I'm afraid we're too late."

Tegan stared at Adam. "He's dead?"

The Doctor nodded solemnly. "Yes."

"What did they do to him?" she said angrily. A cup lay next to the bed. She picked it up and held it to her nose. "They've poisoned him!"

The Doctor took the cup and sniffed it. "No, Tegan, this contained only a mild sleep-inducing agent."

"Then what happened to him?"

The Doctor set the lantern on the floor and studied Adam's face for several seconds then lifted the man's hand to study the nails. "I would guess that his heart simply gave out."

Tegan touched Adam's cheek with her fingertips. "I'm sorry," she murmured.

"Tegan?" A familiar feminine voice echoed slightly through the still dwelling.

Tegan and the Doctor looked back toward the door; Hahmala stood holding a candle and a large basket.

Tegan rose. "Hahmala! Adam's dead!"

Hahmala blinked at Tegan, clearly surprised that the visitor's words were comprehensible to her. "Yes," she responded slowly. "His spirit left us just before dusk. I've come to prepare him for the rest of his journey. But you've come back. We thought that you and the boy had gone. The guards saw you disappear into the rock—"

Tegan nodded. "We did. We returned to the planet that we came from. But I wanted to take Adam back to his home, too, so we came back here."

"In the rock?" asked Hahmala.

"No, another way."

"But," said Hahmala, still perplexed, "I do not understand this. You can speak my language now."

"No, I really can't. It's the TARD—"

The Doctor immediately cut her off. "Yes, we can understand your language. We appreciate all that you did for Adric; he told us how well you treated him. But we really must be going now. Come along, Tegan." He stepped toward the door.

"No," said Hahmala, "you must not go."

"I'm afraid that we must," replied the Doctor.

"Please." Hahmala took a step back toward the door.

The Doctor reached for her arm and steered her back into the dwelling. "I'm sorry, but we can't stay, and you mustn't try to stop us from going."

"But Tegan is our sign. She must remain here."

The Doctor asked, "Your sign? Of what?"

"Of good fortune, of hope for renewal," replied Hahmala. "Those who come from the rock bring new blood and new lives."

"Of course," said the Doctor with a nod of understanding, "your ancestors came from the rock. But you have an established community. You have all that you need here; your village is thriving."

"Yes. But it was not before Ah-Dahm came. There were few babies, and many of those who were born died before they could grow into men and women. But Ah-Dahm brought new blood, and many babies came after him."

The Doctor considered this information for a moment. "Did Adam have children here?"

Hahmala nodded. "Yes. He had seven, and many grandchildren. My grandfather saved this village."

Tegan blinked in surprise. "Adam was your grandfather?"

"Yes," replied Hahmala.

"So he had a life here—a wife and a family," said Tegan.

"Yes."

Tegan looked back at the elderly man. His countenance appeared tranquil. "Was he happy?"

Hahmala smiled. "Yes. He loved his children and grandchildren, and he had a wonderful wife."

"But I thought he wanted to leave the village," said Tegan. "Isn't that why you kept him locked in here?"

Hahmala's expression became somber. "The elders have told me that he tried to leave during the first season that he was here. But after he married, he never tried to go. The door to this dwelling was shut recently so that he would not be hurt. His mind wandered; he was confused. Three seasons ago he nearly fell from the path. We only put the door here to keep him safe."

"I'm glad he had a good life here," Tegan said.

"Yes," added the Doctor. "And his genetic material obviously strengthened the generations that followed him."

"So you see why you must stay?" asked Hahmala. "You will both bring stronger children to the village."

"Children?" echoed Tegan. "Oh, I don't think so."

"No, Hahmala," said the Doctor, "that is not our purpose in coming here. We cannot stay. Please, allow us to leave without difficulty."

"I cannot," Hahmala responded. She stood firmly before the door.

"Please don't force us to restrain you," said the Doctor.

Hahmala turned her head toward the doorway, obviously preparing to call for help. Tegan grasped the other woman's arm, however, and pulled her forward, clamping her hand over Hahmala's mouth.

"Please just let us go," Tegan enjoined as Hahmala's eyes widened. "Please."

The Doctor took Tegan's wrist to lower her hand. "Hahmala," he said, "even if we did stay, we would not bring any children to this village. I am not the same as your people. Much as two different types of lizards that look quite similar still cannot reproduce, your people and I would not be able to create any children."

"But you look like us," Hahmala said.

The Doctor took her hand and pressed it over one of his hearts then against the other. Hahmala's brow wrinkled in confusion.

"I have two hearts," he said simply. "You have only one."

Hahmala withdrew her hand. "And Tegan?"

"She is—" the Doctor began.

"Different, too," Tegan finished.

Hahmala nodded. "I understand."

She stepped away from the door and bowed her head slightly. "You may go. I must attend to Grandfather now. He has lain too long already."

Tegan quickly squeezed Hahmala's hand. "Thank you," she said.

"We wish you and your people well," added the Doctor as he moved toward the doorway. He paused, however, to touch a few circular carvings on the wall. "How did these get here?" he asked Hahmala.

She replied, "My father carved them. We put a few in each home for luck."

"Why do you use these particular shapes?" asked the Time Lord.

"I do not know, " Hahmala responded. "Our ancestors began carving them, and we have always done the same."

"They are very attractive," he commented, then he stepped toward the door.

"Good bye," said Tegan.

Hahmala nodded again. "Wait," she said, quickly looking out the door. "Go that way." She pointed to the left of the dwelling, away from the main portion of the village. "There is a small ladder four houses away. You will not be seen if you use it."

Tegan and the Doctor smiled in appreciation and left the house. They found the ladder easily and descended it quickly without further conversation. Once they had reached the ground, however, Tegan spoke.

"I'm sorry, Doctor, I didn't realize that Adam had been married and had a family here. I thought he'd been their prisoner all this time."

"It's all right, Tegan. You wanted to help him; I cannot fault you for that. And we've managed to leave without difficulties, so there was no harm done. Actually, I rather enjoyed seeing the village."

His pace quickened, as he added, "However, we should return to the TARDIS as soon as possible. There could be other dangers out here."

Relieved as she was to have departed from Tlan-Arana without incident, Tegan's mind was still heavy. She took a breath; she wanted to have this discussion before they arrived at the TARDIS.

"Doctor," she said, trying to use a firm and confident voice, "there's something you need to know about Adric's fall."

The Time Lord strode beside her but turned to give her an inquisitive look. "Really? And what is that?"

"He was trying to avoid Nyssa and me. That's how he stumbled and fell."

The Doctor's steps slowed. "I see."

"I think," said Tegan, "that your conversation left him feeling embarrassed and ashamed. It really hurt his pride. He would barely look at me in the village, and he actually wanted me to leave him here, rather than having to face Nyssa."

"That is unfortunate." The Doctor's voice was flat; his forehead creased momentarily.

"I know you're going to say it's all my fault for pushing you to talk with him, but I really don't think it is. It's not fair for you to blame this on me. I was just trying to point out a potential problem, and if you handled it in a way that was upsetting to Adric, then—"

The Doctor interrupted her. "You're probably right, Tegan."

She stopped walking. "What?"

He ceased his movement, too. "In retrospect, I do not believe that I dealt with the topic as well as I might have. Clearly Adric was upset; I realize that now. However, at the time I felt that I was doing the right thing. I'm not entirely sure, even now, how I might have handled it differently."

Tegan was still somewhat taken aback by the Doctor's complacency. After a moment, she said, "I guess I could have given you some better suggestions instead of just insisting that you speak with him. You've never raised a teenage boy or spent a lot of time around them; I probably shouldn't have expected you to know what to say."

"Perhaps in the future you could provide me with some guidance, should a similar situation ever arise."

"Any time, Doctor." Tegan smiled and began walking again.

"Wait a moment," he said, gently reaching for her arm. "There is one more thing that I would like to say to you."

She stopped to look at him.

"I regret that you became ill; I was not as attentive as I should have been."

Tegan frowned. "But Doctor," she said, "if I hadn't gotten sick, I would never had ended up here, and we wouldn't have been able to find Adric."

The Doctor shook his head. "Miss Tegan, at times your logic astounds me."

Tegan opened her mouth to respond, but a distant howl silenced her momentarily.

The Doctor cocked his head to the side to listen. "Come on," he said, taking her arm again and hastening forward. "Trust me on this, Tegan. We do not want to come face to face with the animals that have made that noise."

With a small shiver as she recalled her long walk across the desert with Adric, Tegan agreed, "Too right."

They hurried along the base of the mesa in the silver light of the two moons.

----------