Tegan looked at the Doctor, aghast. "You mean you're deliberately choosing to go on the run from your own people? In a rackety old TARDIS?"

The Doctor grinned at her and Turlough. "Why not? After all, that's how it all started!"

"So, where are we going now?" asked Turlough.

"Random co-ordinates, unknown destination," the Time Lord replied. "Should stop the Time Lords following us. Now, I wonder what Kamelion is up to?"

Tegan followed the Doctor further into the TARDIS. "Oh, I'd almost forgotten about him," she muttered. She wasn't fond of their new travelling companion.

"Really, Miss Tegan?" came a voice from behind her. "Maybe you should seek medical help for your short term memory."

She spun round and glowered at the silver skinned mechanoid. "Has anyone ever told you it's bad manners to sneak up on people?" she raged at the machine.

"I'm sorry, Miss Tegan, but I did not sneak up on you. I was recharging in my room. When I completed the charge, I left the room. You were passing. I attempted to engage you in conversation. With satisfactory results, it would seem."

Tegan frowned. "Satisfactory results? I'll give you satisfactory results!"

The Doctor grasped her arm. "Not now, Tegan." He steered her away from their newest companion. "Why don't you have a lie down?" the Doctor suggested.

Tegan wrenched her arm free of the Doctor's hold. "I'm going to my room," she stated hotly. "I may be some time!"

The Doctor watched her stalk away. He turned to see Turlough and Kamelion watching him. Kamelion was wearing his usual calm expression, while Turlough had a look of wry amusement on his face. He shrugged at the Time Lord.

"You know what she's like. Best left alone."

The Doctor looked again in the direction Tegan had disappeared. "You're probably right," he agreed with a sigh.

***

Tegan woke with a start. She was laid flat out on her bed, dressed in the blue and green striped outfit she had changed into when she stormed in here...how long ago?

She looked at her watch. The Doctor had given it to her as a birthday present. It automatically reset to local time wherever they landed. It now showed she had been asleep for four hours. As she shook the fuzz out of her brain, she realised what had woken her. The Cloister Bell. A kind of TARDIS early warning system. Galvanized into action, she left her room quickly and headed for the console area.

She entered to see the Doctor dashing round the console, checking monitors. Turlough stood near the inner door, rubbing his hands together in that nervous manner of his. Kamelion was standing beside the hat stand, looking calm. She looked back to the Doctor quickly. "What's happening?" she asked. The Doctor just held up one hand to her, meaning he was concentrating and not to be disturbed. She looked over at Turlough.

He looked unhappy. "The TARDIS has been diverted. The Doctor is trying to find out how and by what."

Now the Doctor spoke up. "We're being drawn towards a source of huge power. I'm trying to break us free."

"Any idea what it is?" Tegan asked.

The Doctor looked up at her. "I've seen the energy signature before. It looks Osirian."

Tegan remembered the Osirians from a recent encounter. They were an ancient race with God-like powers. They had influenced the Egyptians on Earth and countless other races across the galaxy. "Doctor?" Tegan asked fearfully. "It couldn't be Nephthys again, could it? We did defeat her, didn't we?"

"Of course we defeated her, Tegan," the Doctor replied, still working. "Anyway, the source isn't set on Earth." Then he let out a groan.

"What's wrong?" Turlough inquired, a hint of worry in his own voice.

The Doctor thumped his fist on the console in a rare show of anger. "The signal is coming from Mars. Some fool has re-opened Sutekh's tomb!"

***

The stillness of the stone chamber was broken loudly by a shrieking noise, as the TARDIS made its usual protests about leaving its natural environment, the time/space vortex. It solidified in the corner with a sulky thump.

The Doctor emerged, torch in hand. He slipped the lighting device back into his pocket when he saw that there was dim illumination.

Tegan, Turlough and Kamelion followed him out of the TARDIS. As they landed, Tegan had been filling them in on the recent encounter she, the Doctor and former companion Nyssa had shared with the evil Nephthys. Now she was telling them what little she knew about the Doctor's encounter with another Osirian, Sutekh.

Turlough looked around them, taking in the small, bare chamber with hieroglyphs around the walls at head height. "So this is Sutekh's tomb."

"Well, not exactly," the Doctor told them, hands thrust deep in his trouser pockets. "The tomb that actually held Sutekh was in Egypt. This was the location of the machinery that kept him prisoner."

"But if he's dead, what's the problem?" Tegan wanted to know.

The Doctor frowned. "Osirian technology was far in advance of anything currently used on Earth. If it fell into human hands it could be extremely dangerous." As he was talking, the Doctor had been inspecting the walls. There was no obvious door. Tracing the wall drawings, he found the one he was looking for and pressed it. A concealed door swung open. The Doctor grinned at his companions, as if expecting a round of applause. He didn't get it.

"What time is it on Earth?" asked Tegan as they walked out into a stone corridor, also dimly lit.

"Lunchtime, if my stomach is any guide," Turlough stated. Tegan glared at him.

"Mid 21st Century," the Doctor replied, ignoring Turlough's remark. "Mankind is setting out to explore the Solar System. Of course, they have already been to Mars a number of times, but the Red Planet seems to hold a fascination for your people."

They had come to a fork in the corridor. The Doctor seemed torn about which way to go. Before he could resort to his double-headed penny, Tegan proposed an idea. "Why don't we split up and explore separately?"

The Doctor grinned at her. "Excellent idea Tegan! Now, why don't you go that way with..."

"Kamelion!" Turlough interrupted. "You would be much safer in his company and the two of you could spend some quality time together."

"Well, good ideas are coming thick and fast today," the Doctor commented. Tegan shot Turlough a look of pure venom. Turlough just smiled.

"We'll meet back here in an hour. Try not to get lost or into any trouble," the Doctor instructed. "Now, come along, Turlough."

The Doctor and Turlough set off down one branch. Tegan stood at the junction, fuming to herself.

"Hadn't we better get underway, Miss Tegan?" the shape shifter asked.

Tegan sighed. She knew when she was beaten. "All right. Come on, Kamelion." They moved off down the other branch, heading for who knew what.

***

The Doctor and Turlough walked steadily along the corridor, checking the occasional side chamber as they went.

"Why did you push Tegan and Kamelion together?" the Doctor asked out of the blue.

Turlough blinked at him, but the Doctor was striding ahead. He had to run to catch up. "I thought it might be a good idea," he replied, slightly out of breath.

"Is that the only reason?"

"Of course," Turlough said, a little too quickly.

The Doctor stopped suddenly and raised an enquiring eyebrow at his companion. Turlough grew nervous under the scrutiny.

"Well, Tegan has been rather annoying lately. She needed to be taught a lesson."

The Doctor sighed. "I really wish you would all get along with each other." He pushed his hands deeper into his pockets and strode away, leaving Turlough to catch up again.

***

Tegan walked beside Kamelion in silence, looking neither left or right. She was still fuming at that rat Turlough.

"Would you like to start a conversation, Miss Tegan?" the mechanoid said.

"Not really," Tegan snapped. Then a thought struck her. She turned to Kamelion. "You can become anybody at all, just by me thinking about them, right?"

"That is correct. A simple act of concentration on your part will transform me into the person you are thinking about."

"Right, here goes." She stopped and closed her eyes. When she opened them, Nyssa was standing before her. She smiled at her friend. "Hello, Nyssa. How are you?"

"I am well, Miss Tegan," Nyssa/Kamelion replied.

Tegan sighed. "Can't you at least play along? Try to be Nyssa?"

"I can only go on what I glean from your mind. You are still keeping it closed to me."

Tegan frowned. "Yeah, and I always will." She turned and stalked away.

***

Turlough had been surprised by the Doctor's question. He thought he kept his thoughts pretty much to himself. He wasn't used to being caught so wide open. Everybody thought that Turlough was a coward. In truth, his one act of bravery had landed him in the deepest trouble of his life. Turlough's family had been on the losing side during a military coup on their home planet of Trion. While his father and younger brother had been sent into exile (his mother had died when his brother was a baby) Turlough had been spared this punishment. At least initially.

Young Vislor Turlough had been attending the Trion Military Academy. His father had begged him to tow the party line, keep his nose clean and not get into trouble. He agreed, for his father's sake. It took a month. A month of taunts from his Knight Commander about being the son of a traitor. It wasn't the names they called him that hurt. It was the accusation that his father was a traitor. It took four other students to keep him from beating the Knight Commander to death.

As the prison colony of Sarn, where his father and brother had been sent, was currently closed, they had exiled him to a backward planet called Earth, where he had met the Doctor. The same Doctor he had just walked into the back of, because the Doctor had stopped. The Time Lord didn't notice, staring about the chamber they had just entered.

"This is fascinating," said the Doctor, "don't you think?"

The chamber was huge, the ceiling disappearing into darkness above their heads. The walls were flowing colours, stretching as far as the eye could see. In what appeared to be the centre of the room was a crystalline column, also of shifting colours. Turlough had to agree with the Doctor's assessment. It was fascinating. And impressive. And more than a little scary.

"What is this place?" Turlough asked, failing to keep the sense of awe out of his voice.

The Doctor was walking towards the column. "Some sort of central control centre, I should think."

Once again Turlough hurried to catch up with him. The Doctor was looking up the column, which disappeared into the darkness that hid the ceiling. The Doctor held out his hand and gently brushed his fingers against the column. A chime sounded as he did so.

"Isomorphic control systems?" inquired Turlough.

"So it would appear," the Doctor replied, hands now back in his pockets. "I wonder if the walls are the same?"

"Maybe you should ask them." The Doctor had to lean around the column to see where Turlough was pointing. By one of the dozens of entrances to the chambers, he could now see three humanoids, all absorbed in studying the walls.

"Excellent idea, Turlough," the Doctor beamed. "You're full of them today," he added, a twinkle of mischief in his eye. Turlough remained silent as they approached the newcomers.

***

Despite herself, Tegan had begun talking to her companion. She had started by asking about Kamelion's morphic abilities.

"I have organic software, which works with my bio-mechanical components to alter my appearance."

"You mean you're not totally mechanical?" she inquired.

"That is correct, Miss Tegan."

They lapsed into silence again, while Tegan thought this over. Then they discovered the chamber. "Wow! Just look at this place!" exclaimed Tegan.

"It is rather striking," replied Kamelion. He was still in the form of Nyssa, Tegan having thought that it was best leaving him that shape, at least for now.

"You're certainly one for the understatement," breathed Tegan, moving further into the chamber. It was so big it was difficult to see across it. There seemed to be a column in the centre, showing the same shimmering colours as the walls.

"Complex interpersonal conversation skills were not uploaded into my memory banks," Kamelion/Nyssa replied.

Tegan sighed. "You're not kidding," she muttered.

Nyssa/Kamelion smiled slightly. "I am not programmed to joke."

Tegan decided to change the subject. "I wonder what the Doctor would make of this place?"

"You can ask him if you like. He is standing over there."

Following the pointing finger, Tegan caught sight of a group of people on the far side of the central column. The Doctor's fawn frock coat was easily distinguished, as was Turlough's Brendon School uniform. The other three people, although too far away to make out details, were unknown to her. They must be part of the human expedition the Doctor suspected were exploring this pyramid. She was about to shout a greeting when she noticed something. One of the men the Doctor and Turlough were talking to had moved behind the Time Lord. Now he raised his arm, as if to strike the Doctor down!

***

"Hello. I'm the Doctor and this is my friend Turlough."

The three humans spun round, their discussion suddenly forgotten. They gaped at the two seemingly young men who had appeared behind them.

"How did you get here?" spluttered one of them, presumably the leader.

"Oh, much the same as you, I suppose," the Doctor replied, moving past the man who had spoken to study the shifting colours of the wall behind the humans. "Hmmm. This panel is a different colour to the rest, had you noticed?"

"Yes, thank you, we had," said the spokesman sternly. "Now, who are you?"

The Doctor placed a pair of half frame spectacles on his nose, peering closely at the panel. "I told you who we are. I'm the Doctor and this is Turlough." He whipped the spectacles off again and turned quickly to the man. "Now, who are you?"

"I'm Professor Joseph Stark and I thought we were the only people here."

"So you were, until my, erm, craft picked up a disturbance and traced it here. I suppose you activated this." The Doctor gestured to the wall panel behind him, the one that was a light brown compared with the lime green flowing across the others.

"Activate? We did not activate anything, young man. Just what is your business here?"

"Putting right other people's mistakes, Professor Stark," the Doctor said lightly, thrusting his hands deep into his trouser pockets.

"Maybe he has a point, Professor," said one of the other men. "We did touch this part of the wall. Who knows what we might have done?"

"Nonsense, Chapman," Stark admonished the tall, grey haired man. "How can touching the wall do anything?"

The Doctor was gazing about them, checking the other walls for signs of brown. "These walls are touch sensitive control panels, as is the central column, a sort of master control. So, if you've touched any of them, you could have activated some aspect of the Osirian technology."

"Osirian?" snorted Professor Stark, putting his hands on his ample hips. "You give the builders of this place fancy names now?"

The Doctor turned to him and Stark flinched back slightly from his scrutiny. "The Osirians were an ancient and powerful race, who were striding across star systems when your ancestors were still scratching stick men on cave walls. It's best not to mock the older races, Professor. You never know when they might come back and blast your culture into a million bits."

Stark was left standing with his mouth open as the Doctor shifted his gaze back to the walls.

"So the signal the TARDIS picked up came from here?" Turlough asked. He didn't like being sidelined for too long and was determined to make the most of this time without Tegan.

"Indeed," the Doctor replied. He turned to Chapman. "What exactly happened?"

Chapman smiled, pleased to have been brought into the conversation. "When we arrived the chamber walls were a uniform blue. We examined the panel closest to the opening. The Professor touched the wall, causing a chiming sound. He did it a number of times more, causing more chimes. Then the panel changed colour."

Professor Stark's round face flushed. "I am not to blame for anything," he blustered.

The other member of the expedition, the shortest of the trio, was standing behind the Doctor, looking towards the centre of the chamber. Suddenly, he spoke up.

"Look!" he exclaimed, raising his arm to point towards the column.

"Now what, Reid?" snapped Stark as they all spun round. Even from this distance, they could see that the control column had turned completely brown, like the wall behind them.

"This isn't good," the Doctor muttered. "This isn't good at all." He started walking briskly towards the column.

"Now what?" exclaimed Professor Stark. When he realised everybody else was following the Doctor, he hurried to catch up.

The Doctor's long strides got him to the column before everyone else. He was studying the swirling brown colours intently through his half moon spectacles.

"What's happening, Doctor?" Turlough inquired, slightly out of breath.

"Something has been activated. I'm not sure what, but we must find out."

"Why must we?" demanded Stark.

The Doctor turned to him. "And I thought you had an inquiring mind? What are you a Professor of? Lethargy?"

While Stark was spluttering in indignation, the Doctor turned back to the column, flexed his fingers and lightly ran them along the edges of the device. A dull chime rang in the air.

"How come he's allowed to touch stuff, yet criticises anybody else?" said Stark.

"Because he's the Doctor," Turlough replied simply.

***

Tegan took a breath to shout a warning, when she realised that the man behind the Doctor was pointing at something, rather than trying to hit the Time Lord. She looked across at the central column, where the man was pointing, and saw that it had changed colour. Then she saw the Doctor, striding purposefully towards it. She knew something was wrong. "Come on, Kamelion," she said, "I think the Doctor needs us."

***

The Doctor was trying various combinations, running his fingers across the column in a number of patterns. The tone of the chimes changed with each new pattern.

"What is he trying to do?" Stark wanted to know.

"I'm no scientist, just a humble engineer," said Chapman.

"Don't look at me," Reid said. "I may be a scientist, but this place is like nothing I've ever seen."

"He's trying to help," Turlough told them loyally. "It's what he does best."

Any cutting reply from Stark was lost when a booming voice rang around the chamber, speaking in a strange language.

Turlough looked mystified. "I thought the TARDIS translated any language we heard into English," he commented.

"It should," the Doctor replied, scratching his head. Then he snapped his fingers. "But some of the ancient languages of the universe were never programmed into the database!"

The Doctor's companion frowned. "I suppose that includes Osirian?"

"So it would seem," the Doctor beamed at him. "But I have an idea." His fingers danced over the column, coaxing and refining. When the voice came again, some of the words were in English.

"How did you manage that?" Turlough wanted to know.

The Doctor grinned. "I got the programme to repeat, but this time in ancient Egyptian, which the TARDIS telepathic circuits can interpret. Now, once more should do it." Once again, the Doctor's fingers flew over the smooth surface.

When the voice came again, Turlough wished the Doctor had not translated it. "THIS IS THE VOICE OF HORUS, BROTHER OF SUTEKH THE DESTROYER. SUTEKH IS FREE. HE CANNOT BE ALLOWED TO ROAM THE UNIVERSE ONCE MORE. THE DOOMSDAY DEVICE PLANTED INSIDE HIS PRISON ON EARTH HAS BEEN ACTIVATED. THE PLANET, AND SUTEKH WITH IT, WILL BE DESTROYED!"

The distance across the chamber was deceptive. It had taken Tegan and Kamelion/Nyssa nearly ten minutes' brisk walking to reach the central column. The five men clustered round it had not seen their approach, stood as they were with their backs to the two newcomers. Tegan had been about to ask what was going on when the voice she had heard twice before suddenly spoke in English, announcing the end of her world.

In the silence that followed she felt she had to speak. "Doctor, what's going on?"

The three strangers whirled round, startled by her presence. Even Turlough looked like he wasn't expecting her. The Doctor, however, seemed unsurprised.

"Hello, Tegan, Kamelion," he said, while studying the shifting patterns of light closely. "Have you found anything interesting?"

"Only that Earth is about to be destroyed!" she said, wondering how he could be so calm.

"I assume you know these women?" commented the older, stouter member of the group.

The Doctor turned from the column. He looked surprised at Kamelion's appearance, but didn't comment. "Indeed I do. Tegan Jovanka and Kamelion, this is Professor Stark and his associates, Mister Chapman and Doctor Reid."

Mumbled greetings followed, except from Stark, who glared at the newcomers. The Doctor turned back to his study.

Tegan sidled up to him. "I don't like the bit about Earth being destroyed," she whispered.

"Well, hopefully it won't come to that. If I could work undistracted for a while," he finished pointedly, raising his eyebrows.

She nodded sulkily. "Point taken. I'll leave you to it."

The Doctor had already gone back to it, so she walked up to Turlough.

"I see you've brought a friend along," he quipped mildly, nodding to Kamelion/Nyssa, who stood silently at the back of the group.

Tegan smiled glumly. "Didn't do much good, changing it. Still talks like Kamelion, even if it does look like Nyssa."

"It also isn't deaf," Kamelion/Nyssa said huffily.

Turlough smiled slightly at Tegan's discomfort and ventured a question. "Any luck yet, Doctor?"

"Hmm? Oh, that very much depends on your definition of luck. If you mean have I stopped the doomsday device that's going to destroy Earth, then no, no luck. If you mean have I figured out how to stop it, then yes, I might have."

"Well, don't keep us in suspense," Tegan said.

The Doctor sighed. "Kamelion, would you be so good as to step over here?"

"Of course, Doctor," Kamelion replied, reverting to his own form and voice. A mutter broke out among the three members of the Earth party.

"No need to be alarmed. Kamelion is a bio-mechanoid, capable of altering his appearance. He's also a friend of mine."

Kamelion was now standing beside the column. The Doctor turned towards him and began to concentrate. Slowly, the shape shifter began to shimmer and change. His body became swathed in a floor length black cloak, while his head disappeared under a pointed black and red mask. Only two burning red eyes were visible through it. The Doctor stepped back as the transformation became complete. He nodded to himself in satisfaction.

"Who's that?" asked Tegan, keeping her voice low in case the apparition heard her.

The Doctor beamed at them all. "That," he announced, "is Sutekh!" The Doctor slid his hands expertly along the column. With a flourish, he removed them again. "There, that should do it," he commented.

"What have you done?" asked Turlough suspiciously.

"I've initiated a scanning sequence for this chamber. Once it picks up our friend here, it should disable the doomsday device on Earth."

They didn't have to wait long. A beam of pale light shot out from the column, playing over Professor Stark. He flinched but the beam quickly passed over him and on to Chapman. It passed over them all, until it reached Kamelion. The beam passed from his feet to his head, then back to his feet. After a few seconds, it shut down.

Within moments, the voice was back. "THIS IS THE VOICE OF HORUS, BROTHER OF SUTEKH THE DESTROYER. SUTEKH IS FREE AND INSIDE THIS COMPLEX. THE DOOMSDAY DEVICE ON EARTH HAS BEEN DEACTIVATED. THE DOOMSDAY DEVICE INSIDE THIS COMPLEX HAS NOW BEEN ACTIVATED. SUTEKH MUST NOT BE ALLOWED FREEDOM WITHIN THE UNIVERSE."

Tegan's jaw dropped. "Great plan, Doctor. Save Earth and kill us all!"

"That was unforeseen," the Doctor admitted, looking flustered. "Come on, quick. Back to the TARDIS."

Turlough leading the way, they ran across the chamber, heading for the entrance he and the Doctor had used. Even the Earth party ran. The Doctor was bringing up the rear when he realised someone was missing. He turned back, to see the figure of Sutekh standing beside the column. "Come on, Kamelion!" he shouted.

"I should remain," the bio-mechaniod said. "In case it senses I have gone."

"I'm not leaving without you. Now come on," the Doctor ordered. Kamelion obeyed, running with a speed a human could not manage, to quickly rejoin the group.

Turlough's sense of self preservation led him unerringly back to the TARDIS. The Doctor let everybody in, except Kamelion and himself. "Tegan, see that everyone is comfortable. I'll be with you shortly." She looked like she was going to argue, then thought better of it. She disappeared inside the TARDIS.

"So, you have decided to leave me after all," Kamelion said. He sounded resigned.

"Not at all," the Doctor told him. "But you were right, the systems might detect your leaving. We need to wait until the last possible moment."

"How will we know?" Kamelion asked reasonably.

Far away, they heard an explosion. The floor rocked under them. The Doctor looked at Kamelion. "I think we'll know."

When chunks started to fall from the roof of the small room, the Doctor pushed Kamelion towards the TARDIS. "Time to move, I think," he said, following him inside. As the TARDIS dematerialised, the entire complex exploded in a fireball of brilliance.

***

On the TARDIS scanner, a new crater appeared on the surface of the red planet. "How come it didn't destroy Mars, like the other device would have destroyed Earth?" Turlough wanted to know.

"I localised the explosion to just the complex," the Doctor said. "I couldn't do that with the Earth device. Now," he added, looking at Stark and his two colleagues, "we should get you gentlemen home."

As the Doctor began setting co-ordinates, Tegan spoke up. "Doctor, can I ask just one thing?"

The Doctor looked over at her. "What?" he asked.

Tegan gestured towards Kamelion, still in the form of Sutekh. "Can you change him to something more appealing?"

END