Spoilers: All of season 3. :) Absolutely AU from there on out. A "character spoiler" for "The Sontaran Stratagem/The Poison Sky." Assuming such a thing as a "character spoiler" exists.
Disclaimer: "Doctor Who" and related characters and situations are the property of the BBC. No money changed hands and no copyright infringement is intended or implied.
Author's Notes: This isn't really a sequel to "The Faithful Companion" but it is in the same universe. It also touches, just barely, on "The Hyacinth Girl." And definitely goes AU from the end of season 3 (or series 3, whichever).
This is unbetaed, so please let me know what you think and whether there are any places that you think things get a little rough. And feel free to tell me in whatever terms you think you need to, even if those terms are "You totally suck and your dialogue is dumb." Seriously, I'm a big girl, and I promise I can take it. :)

Donna Noble had no idea what that sound was in her living room, or what was making it, but she knew it didn't belong there. So, with cricket bat in hand, she crept out of her bedroom and waited in that deep shadow beside the refrigerator to see if there really was an intruder.

A tall individual walked into the kitchen and Donna came out, bat raised, with an Amazon yell.

Her intruder stumbled back, arms raised, yelling in surprise. "Donna! Donna, it's me! It's the Doctor, it's me!"

"Martian Boy?" Donna paused, just as she was about to bring the bat down, soundly on his head. She got a good look at his face, in the light from her front windows. "What are you doing here, Doctor? Do you know that it's two in the morning?"

The Doctor blinked. "Is it? I thought…o'course, that does explain why it's so dark."

Donna stared incredulously. "You hadn't picked up on the fact that it's dark?"

The Doctor gave her the most miserable look she'd seen in a long time and Donna sighed. "I'll put the kettle on."

It was over steaming teacups that the Doctor told Donna Noble, of all people, the story of his past year with Martha, which was actually two years because one didn't count, and his unfortunate adventure on the Titanic.

"…So I rewound the whole year. Nobody remembers it. You don't. I'll bet you barely remember who Saxon was," the Doctor finished, having had to go back and re-explain the timeline.

"Of course, I do," Donna returned sharply. "He was Prime Minister, if only for a few days. But he went a bit psychotic on television at the end. Started calling himself 'the Master,' didn't he? And for the President to have died like that…that's not something you forget overnight. Anyway, then the picture cut out. I suppose that was the year?"

The Doctor nodded. "And then Martha left me."

"Good on her."

The Doctor smiled, and Donna was astonished to see that there wasn't a hint of ruefulness or self-deprecation in it. "Yes, it was rather, actually."

"So what brings you to my flat in the middle of the night?" Donna asked.

"Well, I need a—hang on. This is a really nice flat, Donna," the Doctor said, just noticing. And it was. It was definitely a woman's flat, but all the furniture looked quite comfortable, and there was plenty of space.

"Yeah, well, I got a decent job now," Donna grinned.

"Good for you, Donna Noble!"

"So…you're here because…?"

"Oh, yes! Well, the TARDIS started picking up some odd fluctuations in the time stream, and I need to go have a look, but…well, I was hoping for some help. Sometimes, it's just better to go into this kind of thing with a friend." The Doctor frowned. "Of course, with you having a job and all, I suppose I should go ask someone else."

Donna smiled at how disappointed the Doctor looked. "I've got a little free time. But you'd better get me back here before Tuesday!"

The Doctor grinned. "Then, Donna Noble, we'll be off!"

The Doctor threw open the doors to the TARDIS and led Donna out onto her first alien world. And he had to admit, as much as it was occasionally a pain to break in a new traveling companion, their first time on another planet was always fun to watch.

Donna did not disappoint. "The sky is red! Doctor, the sky is red! You took me to a world with a red sky!"

"Yeah," the Doctor grinned. "Red sky, purple plants, air is sweet-tasting. Alien planet, Donna."

They'd landed in a garden full of—to a human, anyway—very bizarre colored plants.

"The air is sweet-tasting! Why is that?" Donna leveled a glare at the Doctor that would have been a little frightening, if he hadn't known for a fact how disconcerted she was.

The Doctor leaned down and pulled a small purple leaf off of a bush. "On your world, purple chlorophyll doesn't exist much, but it is there. On this world, it functions best under the red spectrum of light, and gives off glucose. So, red sky, purple plants, sweet air. Care to see what the people look like?" He offered his arm.

Donna laughed nervously, but took his arm and put a brave face on. He grinned. Donna would adjust just fine to this trip.

The local market was full of color. More so than Donna was used to, since the planets inhabitants were tinged a light yellow. But as much as he was enjoying Donna's reactions, the Doctor became more and more concerned as they strolled through the town.

"What is it?" Donna asked.

"This planet's development has been retarded by about…six centuries," the Doctor replied. "It should be about the same stage of development as yours. Instead, they're a good deal behind."

Donna blinked. "So someone's…perverted their history?"

The Doctor smiled as he was hit with a flashback. "Completely. The thing of it that's truly puzzling, though, is that they managed to do it without damaging the timestream much at all. Just enough to give off a ripple or two, but not enough to alter much else."

Donna stared at him oddly.

"Temporal mechanics."

"And why are we smiling about this?"

"Not about that. You're not the first person to accuse someone of trying to pervert history," the Doctor grinned.

"Oh?"

"I used to travel with a girl—"

"Rose?"

"No! You Earth girls. Always thinking everything revolves around Rose! I only lost her into another universe, after all. Why should that bother me?"

"Sorry."

"Anyway, her name was Peri. Not always the brightest of your kind, but she had her moments," the Doctor grinned. He sobered some and said, "I was actually rather horrible to her once, but she stuck with me when I didn't deserve it. And she put up with my terrible dress sense."

"Because pinstripes and plimsolls are a big improvement," Donna said.

"Believe me, if you'd seen that coat, you'd think they were," he laughed. "It was a fun time, though."

"What happened to her?"

"She got married the King of Krontep. Lived out her life there, and was very happy, so I've heard."

"You don't know?"

He frowned and didn't answer.

"I think I'm starting to see why Martha found you so difficult," Donna laughed.

He gave her a dirty look as they rounded a corner, which he would spend the next several days cursing himself for. It's very easy, while engaged in giving someone a dirty look, to miss things to which a more attentive individual would have adjusted. They had just turned into a very narrow side street, headed for the town's meat market, and everyone knows that narrow side streets are always troublesome spots.

In this case, he missed the two, very obviously non-native—they were slightly too orange to be local—and thuggishly shaped, males who jumped him from the side farthest from Donna.

BAM! Blue and white spangles exploded in his field of vision. Another hit on the back of his head, and he collapsed to his knees.

"Oi!" he heard Donna yell. "Hands off the Martian!"

There was a solid whack from above him, and one of his attackers yowled in pain. Then The Doctor saw Donna fly above the ground and hit the other side of alley with a sick sounding thud.

"Donna?" the Doctor called anxiously, ignoring how the speech hurt his head. She had to be okay. He couldn't stand to loose any more of his friends.

She stirred and looked like she was going to try to get back into the fray when one of the two assailants pointed a threatening-looking gun right between her eyes.

"Don't. Even. Breathe."

Donna froze. The Doctor used the distraction of the two men to drop a key to the TARDIS onto the ground. He hadn't made Donna a copy, and he still had another spare in one of his pockets or another. She'd need it. If these men didn't want her, then she might be able to get help. At the least, she could get home.

"We only want the Doctor, see? You freeze and we'll let you go free, 'kay?"

Donna had seen him drop the key. She met his eyes.

"Do as they say, Donna. I'll be fine," the Doctor urged her. "Go back to the ship. Tell the central computer 'Emergency protocol 47.'" The Doctor didn't know how much these thugs knew, but he wasn't about to say the word "TARDIS" unless he knew it was safe to do so.

Donna nodded. "Good luck, Martian boy."

"Idiot humans. Everyone knows Martians are blue," one of the men muttered. They hauled him up and dragged him off. As they rounded a corner, headed in the opposite direction from the TARDIS, he saw Donna pick up the key.

Good girl, Donna! And good luck, he thought.

Donna sprinted back to the TARDIS and rushed inside. She turned to the central column with its dizzying array of controls and gave into a brief moment of panic before she pulled herself together and started hunting around for a recognizable control. A quick search of the central console revealed nothing but post-it notes covered in circular pictograms, a crickit ball, and a large mallet. Donna was growing frustrated. "Come on, you stupid machine! How do I tell you emergency protocol 47?"

The odd grinding-wheezing noise started up as the TARDIS took off. Donna blinked in surprise. "Okay, good. Now, if only I knew where we were going."

Donna sat down in the jump seat and tried not to worry or think about anything. She was totally unsuccessful, and so when the time rotor finally stopped moving, she was in such a supreme state of agitation that she practically ran for the door and flung it open.

On the other side of the door, a beautiful, dark-skinned woman wearing a slightly puzzled smile was sitting at a desk in an office. But the smile faded when she saw Donna.

"You're not the Doctor," the woman said.

"No. Who are you?" Donna demanded, in no mood to be polite to anybody.

"You're in my office. Who are you? And what are you doing with the TARDIS?"

"Where. Am. I?" Donna demanded, the edge in her voice going past hard and into ferocious.

"The United Nations Intelligence Taskforce headquarters in London. I am Doctor Martha Jones, medical officer. And unless you have a damn good reason—"

"Martha Jones? The Martha Jones? The one that saved the world?" Donna broke in. "The Doctor told me about you. The TARDIS is smarter than she looks."

Martha blinked.

"My name is Donna Noble, and I need your help."

"And you have no idea what species these creatures were?" Martha asked for what seemed like the tenth time.

"They were orange! I don't know of any orange aliens!" Donna answered, trying not to shout. The UNIT personnel didn't seem to appreciate it when she shouted.

Martha looked at the rest of the table. "Alright. We're going to see if we can identify who they are first, otherwise we'll just be sending our team on a suicide mission."

She knew it was pointless. They'd never work out which aliens had taken him. UNIT's information on the inhabitants of the universe covered an estimated less-than-one-per-cent of the total species in existence. And a lot of that information was sketchy. There were also rules about who they could send where and how they could do it. There was no way UNIT would authorize a team to simply climb inside the TARDIS and hope for the best.

Donna looked back at her angrily. She knew it was pointless too, but she seemed less inclined to be nice about it.

"In the meantime, ma'am," broke in a new voice, "we'll try and find you somewhere to sleep tonight."

Martha shot Ross Jenkins a grateful glance. He had a calming effect on people.

"I'll just stay in the TARDIS," Donna told him, "but thank you." Donna exited the room.

Martha got up and exchanged a few words with the researchers before heading back to her office. The TARDIS was still there, and to her surprise, Ross was as well.

"Private," Martha greeted him.

"Doctor," he replied with a slightly embarrassed smile. "I need to ask you to allow me inside the TARDIS for a moment."

Martha gave him a confused look.

"I doubt you want to keep it in your office, so we're going to move it down to the archives until we can either return it to the Doctor, or he comes to claim it," Ross explained.

"But in order to authorize the move, someone has to be sure that it won't blow up or something," Martha nodded.

"In this case, it's mostly a formality," Ross said. "Being Time Lord technology, we'd never stop it, even if it would blow up. And you know we trust the Doctor. I just need to go in, look around once, and leave."

Martha nodded. "I'll let you in." She opened a desk drawer and pulled out an ordinary-looking Yale key. Attached to it was a tiny black thing that looked like a micro-chip.

The TARDIS door unlocked and Martha allowed Ross to go first before following him inside. She closed the door behind her out of habit.

"Holy—" Ross cut himself off, staring around in surprise. "It's a lot bigger in here than it looked out there!"

Martha laughed, running her hand over a coral strut near the door.

Then she heard a wheezing noise. She turned and desperately pulled at the door handle, but the door wouldn't open. "No, no, no!" she yelled. "You have to let us out!"

"What's going on here!" Donna demanded, running into the console room.

"I'd like to know the same thing," Ross said, looking at Martha.

"The TARDIS kidnapped us!" Martha answered, kicking the door irritably.

"It did?" Donna sounded perplexed.

"Oh, she's smarter than you think," Martha said ruefully, turning to face her. "Fully sentient, in fact. More so. She actually talked to me once."

"She's not just a machine?" Donna asked.

"He didn't tell you, either, eh?"

Donna smiled. "This is only the second time I've met him."

Martha grinned. "He does tend to escalate things, doesn't he?"

The two women laughed.

"Ladies?" Ross said.

Martha looked at him and this time it was her turn to give an embarrassed smile. "Apparently the TARDIS felt that I needed to be around to rescue the Doctor. Whether she meant to get you into the bargain or not, I don't know. But I have a feeling that there's no getting out now."

Ross blinked. "Well in that case, do we have any idea where we're going?"

"It took about fifteen minutes for me to get to you from that planet," Donna offered.

"Well, that doesn't give us a lot of time," Ross said. "Tell me everything you remember about that place."

Martha looked at him curiously.

"I've been…asked to participate in a rescue mission. I refuse to do that without knowing as much as I can about where I'm headed. Tell me everything you remember about everything. Even if you already went over it in the briefing back there."

Martha grinned. If the TARDIS had gotten Ross by mistake, it was a good mistake. Donna started running down all the facts she could remember.

They stepped off the TARDIS back onto the same planet Donna had left, and she sighed. "I can take you to where he was taken, and show you which direction they took him, but after that, I have no idea where to go."

"After that, you'd better let us go on ahead," Ross said.

"Not even the slightest chance, soldier boy," Donna answered sharply. "The Doctor brought me along because he needed a second. I'm not disappearing just because it could get dangerous!"

Ross blinked. Martha looked at Donna with approval for the first time.

"Fine. Just…if I ask you to do something, don't hesitate, okay?" Ross said, realizing he was outnumbered.

After they'd gotten as far as Donna could take them, some judicious questioning of the locals managed to get them to an intimidating looking compound outside of town. Around the outside, more of those slightly-too-orange-to-be-human individuals patrolled near the fence, accompanied by some threatening animals with large teeth and claws, and some very impressive gun-shaped objects.

"Okay, three people to mount a rescue against a facility about which we know nothing," Ross said, sounding not entirely pleased. They were hiding just on the other side of a hill outside the compound, looking down on it. That fence with the patrols was about three meters tall and topped with something that looked like razor wire. Whoever had built the place knew what they were doing.

"UNIT is going murder us when we get back," Martha agreed.

"They've got motion sensors, too," Ross pointed. "There, and there."

"Those dog-things don't seem to smell too well, though. We're upwind and they aren't scenting us," Martha observed.

"Snipers in that watchtower."

"And the main gate's got a key pad and a magnetic lock system." Martha squinted. "That looks like a fingerprint scanner, too."

"A lot of this stuff seems very human," Ross pointed out.

"There's probably other systems we don't see," Martha said, "but you're right. There does seem to be a lot of borrowing going on."

"I think," Donna said, breaking in, "that we're going to have to find another way inside."

"Not likely we will," Ross answered. "We've got no resources, no back-up, and no way to get any."

"We can't just do nothing!" Donna said.

"I'm thinking, I'm thinking!"

"Ah…I have a very bad idea," Martha said slowly. Ross and Donna turned to regard her curiously.

A rock bounced off the head of one of the guards at the gate.

"Ow!" he exclaimed.

Ross flung another one at the next guard as hard as he could. Martha had joined in with enthusiasm, pelting the guards with rock after rock, as hard as they could.

"Stop, now!" one of them yelled, raising his weapon.

Martha and Ross cheerfully ignored him, coming closer. They both seemed very focused on the gate.

Now all six guards were training weapons on the two humans who were standing less than five feet away from them.

"Stop! Now! Or you will be shot!"

"I love it when they take charge," Ross said, dropping to his knees with his hands up. Martha followed suit. In short order, their arms were restrained behind them and they were being frog-marched into the facility.

No one noticed the redhead wearing a small Yale key around her neck. They didn't see her follow the group into the compound, watch from quietly in a corner as the two new prisoners were processed and tagged with a very low priority. No one saw her follow to see where they were placed. Everyone's eyes seemed to slide right across her, like they just didn't want to look at her.

Martha and Ross were placed in a secure enough cell to prevent their escape, but it was buried in the compound and they both knew no one would ever come for them again. If the plan didn't work, they'd be there for the rest of their lives.

"Now it's up to Donna," Martha breathed.

"She's traveled with the Doctor once before, right?" Ross asked.

"That's what she said," Martha said.

"So, she's done this sort of thing, then?"

"She didn't tell me what happened. Traveling with the Doctor… It's almost never the same thing twice."

"So, she has no clue what to do next, then. That's not encouraging."

Martha gave him a look that said she was trying not to think the same thing.

Donna wandered around the facility a bit, getting her bearings. The layout was straightforward. The building that they'd seen from the outside looked like a huge processing and office building. There were elevators leading to four levels underneath that. On each of the levels, two long straight hallways ran at least double the length of the compound yard above ground. They were linked at regular intervals by connecting hallways.

Martha and Ross were being kept in the very bottom, a sixth level accessible only by stairwell. The fifth level contained a lot of laboratories and a few busy-looking aliens. The orange people were all wearing either a guard's uniform, or a long gray coat with black edges and lots of pockets over other clothes. It wasn't until Donna realized that half of them were carrying papers and charts that she guessed they were scientists and the gray coat was this species version of a lab coat.

Levels four up to one were more of the same, but the people on those levels seemed less serious than the ones below.

Donna finally turned to go back and investigate the two bottom levels more closely when she discovered that while she hadn't had to do anything to get out of them, she would need a magnetic key card to get back in.

"Okay, not panicking. There must be some way back down," she told herself quietly. She stood by the stairwell and waited. Several moments later, two men came along. One of them swiped a card, and they headed down the stairs. Donna waited until the last moment and then caught the door and followed them. The next door needed a card as well, and she only just made that in time before she was trapped in the stairwell.

The fifth level was emptier than the fourth had been, and so Donna was able to wander around without risk of being seen by too many people. But this time, she checked each door closely. Nearly all the doors she tried were open, and led into either laboratories or offices. Three were locked, and two had no windows on the doors. There was also a big central room that looked like an interrogation chamber in an American police show.

Two men came out of one of the locked rooms, and Donna caught that door just in time to slip inside.

"Brilliant," she breathed. A storage locker. After a brief search, and a frustrating struggle with one of the locks, she managed to find the Doctor's Sonic Screwdriver. In the same drawer was a banana, a very long bendy tube, three paperclips, and a small wallet with a blank piece of paper. With a mental shrug, Donna scooped up everything but the banana, and went back into the hallway.

After some brief mental deliberation, Donna decided to try the locked door farthest away from the stairs. It was on the opposite corner of the level, in fact. So she marched over, and pointed the Sonic Screwdriver at the door.

It popped open with some a few gold sparks and a slight crunching noise.

"Dammit," Donna whispered, hoping no one had heard that.

"Hello? Who is that?" the Doctor asked as Donna entered the cell.

"I'm Luke-Bloody-Skywalker. I'm here to rescue you," Donna answered.

The Doctor grinned. "I bet you've always wanted to say that."

"You have no idea," she replied as they left the little room. "Let's go get Martha and that UNIT bloke."

The Doctor caught her hand as they started running down the hallway. "UNIT bloke? You brought someone else with you?"

"He was…just there! Is this really the time?" They reached the stairs.

"Give me the Sonic," the Doctor told her.

Donna handed it over, along with the rest of the things she'd recovered.

"Oh, Psychic Paper, never mind the Sonic," the Doctor said with a huge grin, swiping the paper through the card reader.

"Psychic Paper?" Donna asked with disdain, as they raced downstairs.

"Sure, it's paper that…why do I always end up explaining the same things over and over?" the Doctor said. "And, by the by, where is my banana?"

Donna gave him a withering look.

They exited the stairwell to face some very surprised-looking guards.

"Hey, what are you—!" He might have continued speaking, but Donna had landed a solid punch right on his chin, knocking his head hard against the wall. The Doctor leveled the Sonic Screwdriver at the other's face. They both fell, out cold.

"Donna," the Doctor breathed in surprise, "you are a very violent woman."

"After you interrupted my wedding, I realized there was more out there to protect yourself from than I had thought, and decided I'd better learn how," she answered.

"Useful, that," the Doctor said. "Come on!"

They raced down the corridor to Martha and Ross's cell. The Doctor had it open in just a few seconds, and the two bounded out.

"Doctor!" Martha exclaimed, throwing her arms around him happily.

The Doctor returned her hug, but Donna didn't like the look on his face. He seemed very sad about something.

Martha must've sensed it because she pulled back. "Doctor?"

"Oh, Martha…," he said. "I wish we had time to talk now, but…it's good to see you again." He smiled, still a little sadly.

"We'll figure it out," Martha assured him. "I found time to make you talk to me before, didn't I?"

The Doctor smiled properly at that. "Never would take a half-answer from me, would you?" He looked around. "You must be the UNIT bloke, then! I'm the Doctor." The Time Lord seized Ross's hand and shook it so forcefully that his teeth must've rattled.

"Private Ross Jenkins, assigned to the United Nations Intelligence Task-Force, and it is an honor to meet you, sir," Ross replied. His voice was unaffected by the enthusiastic handshake, but Donna could see there was a lot of effort going into that.

"Okay, we've got the Doctor back," Martha said. "Let's get out of here."

"Can't do that, yet, Martha," the Doctor replied.

The three humans looked at him curiously.

"This facility houses a machine that's broadcasting a low-level mental damping field across the planet," the Doctor explained. "It's how these people's progress has been slowed. Someone's been dumbing them down."

"Where is it?" Martha asked curiously.

"The building above ground," Donna informed them. "I've been through the rest of this place. There's nowhere else to put it. It's all offices and laboratories."

"It'd broadcast better from the surface, anyway. In fact, it's probably broadcasting to a satellite somewhere, which is blanketing the surface," the Doctor agreed.

"Wait. Laboratories? What are they studying?" Ross asked.

"Let's find out," the Doctor grinned.

It took almost no time to get into one of the laboratories, and with a little help from the Sonic Screwdriver, the Doctor was browsing through one of the computers while Martha, Donna, and Ross sifted through some notes in a folder on the table.

"'…the resilience of the temporal matrix was relatively unaffected by incursion number 6683, though there was a slight variation in the localized temporal state. Slight oscillations between…' What on earth are these numbers?" Donna said, reading off from a paper on the table.

"Coordinates on the Rassilon Scale of Temporal Stability," the Doctor informed her from his place at the computer.

When penetrating stares at the back of his head were ineffectual at producing further explanation, Martha said, "What is the Rassy-man Scale?"

"Rassilon," the Doctor corrected absently. "It's a way to measure changes in time. When the time line is fixed, it has a low rating on the Rassilon Scale. A high rating indicates a time line in flux. Donna, remember how I said that the TARDIS had registered odd fluctuations in the time stream? The Rassilon Scale is how those are measured." He turned from the computer to face them. "These have been experiments in the strength of changes that can be made to the time line before a certain critical point is reached. It doesn't ever say what that critical point is."

"Six hundred years of missing development is a pretty serious change," Donna observed.

"Ah, but they were clever about how they did it," the Doctor pointed out. "They only changed the relative intelligence of the population. A tiny little change, really. Over time, the accumulated effect to these people is quite large, but the impact on time as a whole is quite small. Quite brilliant, really. In an evil sort of way."

"You look like there's a bigger problem here somehow," Martha said.

"The Rassilon Scale was created by the Time Lords. The Miasimia Gorians shouldn't even know what it is," the Doctor informed them.

"What is a My-as-symmia-korean?" Ross asked curiously.

"Miasimia Goria," the Doctor corrected, pronouncing the name very slowly, "is where the Orange People are from. We need to shut this facility down. They've interfered long enough."

"Not to sound callous and uninterested, but these people aren't really our responsibility," Ross pointed out.

"No," the Doctor replied, "they're mine. There are no other Time Lords left. I'm the only one who can help them. I won't force you to stay, but it's got to be done."

Ross nodded. "Good enough for me. How can we help?"

"Now you want to help?" he asked.

"I needed something to put on the paperwork I'll have to fill out when we get back," Ross shrugged. "Sad to say, though, I don't exactly have any C-4 on me."

The Doctor looked at him in surprise. "Oh, Ace would've loved you. Now…what? Any ideas?"

"You'll need a really good plan," a new voice announced. The four looked up to see five Miasimia Gorians coming in the door. One was dressed like the scientists. The other four were carrying guns.

"You always end up getting caught, don't you?" Donna demanded, raising her hands in surrender.

"Not now, Donna," the Doctor said, as he copied her.

They were led to a room on the level above ground, where they made to wait. The guards were still carrying those guns, and they didn't seem even slightly disinclined to use them.

A orange person entered, this one female, dressed in a slightly more polished version of the uniform Donna had seen the scientists wearing.

"Four of you, then? Doctor, how do you manage to attract the loyalty of these humans? It is a bit impressive," the woman said.

"I think it helps when you don't undermine the history of an entire species," the Doctor snapped.

"Yes, you've certainly never negatively impacted the timeline of any species," the woman said.

The Doctor gave her a sullen silence.

"Good, Doctor. No one likes a hypocrite," she remarked.

"Why are you doing this?" Martha asked.

"To see how much of the timeline we can change before the Doctor noticed, of course," she said.

"What?" The surprised question came from all four prisoners at once.

"The Doctor views himself as the guardian of time. We wanted to know just how closely he was guarding it," she said.

"You held these people back out of curiosity?" the Doctor asked in a quiet voice. Martha and Donna both froze. They had heard this note in his voice before and terrible things had followed after.

"Not mere curiosity, Doctor," she replied carelessly. "Of course there are always larger goals." She turned to the guards. "Take them back to their cells. Be sure they can't get free this time." With that, she swept out.

The guards escorted them out of the office, and that was when Martha and Ross pounced. If the Doctor had been impressed with Donna's new-found skills as a fighter, he was rendered speechless to see Martha in action.

Martha noticed. "A year wandering the Earth, running from the Master. And then I joined UNIT. Surely you knew I'd be trained in at least some hand-to-hand combat?"

"I just never thought of it," the Doctor said. "I'm not used to thinking of you as dangerous."

Martha smiled and touched his arm briefly. The four of them turned and ran down another hallway, headed for the center of the facility. But the hallway was a lot shorter than they expected, and if not for the railing that stopped them, they all would have run straight into a huge pit, occupied by a massive machine that dropped down for at least the first two levels of the facility.

"Well, it's not quite the endless blackness we saw at the end of the universe," Martha said, staring down the edge of the pit.

"It'll do anyway," Donna breathed transfixed by the long way down.

"How do we shut this thing down?" Ross asked sharply, snapping them all back to the moment.

"Pull the plug?" Donna suggested.

"No good," Martha said. "Someone would be back to do the same job in less than two weeks."

"We've got to overload the system, somehow," the Doctor agreed, running a hand through his hair. "And we've got to do it so thoroughly that we can persuade the machine to explode and destroy the facility,"

"C-4 unnecessary, then," Ross said with a grin.

"Ace would've really loved you. Donna, you're with me. Martha, go find a fire alarm, or escape siren, or something. Get them to evacuate the building. Ross, you're the guard. Keep anyone from getting to Donna and me before we've done our job."

The group split up, Donna following the Doctor. The two of them ran around to the other side of the machine and followed a very thick cable attached to the ceiling into a tiny room full of controls. He aimed his Sonic Screwdriver at the console and pulled up a schematic of the machine.

After he'd examined it for a moment, he said, "Donna, press down on that button there." The Doctor pointed. "That is the override for the emergency system that prevents this machine from going critical. By the looks of this, it's a dead-man switch, so press down and keep holding it. Don't let up."

Donna pushed down. "So we're going to demolish the whole facility? The last time I saw you, we ended up watching the beginning of the Earth before blowing up all those spider things. Are you always blowing things up?"

The Doctor frowned. "Sometimes I tear them down." He sighed. "I think I'm actually a bit of a danger, really."

Donna laid her free hand on his shoulder. "Wouldn't have you any other way."

The Doctor smiled a bit at that, still working with the controls.

"Oi, why would you build an 'override' for an emergency system, anyway?" Donna suddenly said.

"Start up and reboot procedure," the Doctor replied, not looking up from what he was doing. "The emergency system handles power spikes, but this machine draws more power starting up and shutting down than what it needs to just run. Without the override, the emergency system would automatically halt any attempt to turn this machine off."

"That's not a very good design," Donna said.

"Actually, it's a useful precaution. An interfering menace who isn't as smart as I am," the Doctor explained, ignoring the roll of Donna's eyes, "might try to turn this machine off without using the override switch. If they couldn't find it, they couldn't shut it down." The Doctor pressed three more controls and stood up. "That should just about do it."

A klaxon whined from somewhere overhead.

"That alert sounds a bit like a peacock," the Doctor said, making a face.

"It's horrible, that's how it sounds. Have I held this long enough?"

"Ten more seconds."

Donna and the Doctor waited. As they stood there, an ominous rumbling began low in the floor. First they only had a vague feeling of vibration that seemed to be more in their minds than in reality. Then they felt it in the backs of their jaws and the insides of their ears. Then it crawled down their spines until the whole facility was shaking under their feet.

"Okay, now!" the Doctor yelled, grabbing Donna's hand. The two of them bolted from the room heading for the door.

"It's about time you showed back up!" a nervous-looking Ross said as he joined them, headed out of the machine room. They all ran for the front door.

"Where's Martha?" Donna asked.

"Here!" Martha said, coming out of a side corridor. The four of them raced for the door and burst out into the red sunshine outside, legs pumping furiously for the gate.

"Stop! Stop right where you are!" yelled one of the guards.

"Run for it, mate!" Donna shouted back. Nobody slowed down. Behind them, people started emptying out of the facility like ants from a disturbed hill. The guards took stock of the situation and began running too.

The rumbling in the ground was crawling infinitesimally higher in pitch, but as the four time travelers raced through the gate, Donna caught a high pitched whine starting, and beginning to slide down the scale. The Doctor was leading them towards the hill they'd hid behind earlier. Donna reached the slope and started up. She'd only just made it to the top when the falling whine and the low rumbling met on the same pitch.

BOOM!

A huge shower of dirt flew up from under the compound. The walls of the building were laid flat to the ground for a moment, and then the ground itself peeled back from the center of the blast. The Doctor, Ross, and Donna tumbled over the crest of the hill and landed on one another in a very undignified heap.

"Martha, Martha, Martha, Martha," the Doctor started muttering, disentangling himself from the other two and heading for the hilltop again. Donna looked around and couldn't see Martha anywhere.

Donna and Ross scrambled after the Doctor as fast as they could.

When they got to the top of the hill, they looked out to see Martha surrounded by five Miasimia Gorians, all pointing weapons at her head.

The Doctor almost started running for her. Donna and Ross dragged him back down.

"Think!" Ross hissed at him. "We have no weapons, no plan, and no advantage!"

"We're not going to leave Martha!" the Doctor replied angrily.

"Yes, we are," Ross returned sharply. "We're going to go back to UNIT. There are more than a few protocols surrounding both the capture of one of our own and an appearance of you, both of which enable us to put together a stellar rescue team. We're going to get very, very big guns, and a whole team of unreasonably large individuals who enjoy explosions even more than me. Then you're going to take all of us to their home planet where we will begin instigating more mayhem than could possibly be fair until we get Martha back."

The Doctor blinked. "Fine, but we do it my way."

"I think UNIT can live with that," Ross answered with a grin.

"Come on, then!" Donna said, setting off at a quick jog towards the TARDIS.

The three of them didn't speak at all on the way back, Donna mostly busy catching her breath, the Doctor deep in thought, and Ross working out just what he wanted to say to his superiors to ensure the fastest possible response.

The Doctor parked the TARDIS just inside the front doors of the UNIT headquarters and strode out of the doors with a bang. The expression on his face at that moment was the one that had led the Daleks to name him 'The Oncoming Storm.' Ross and Donna followed him, taking up flanking positions on either side. In step, they walked purposefully towards the main office.

A bored looking secretary looked up and saw them coming. She spoke up quite loudly and said, "Doctor? We've been expecting you. Briefing room three, please."

After that dramatic of an entrance, none of them had been expecting to be stopped by a secretary. The rescue team of three came up short.

"Expecting me?" The Doctor's voice was so squeaky that Ross actually looked startled.

"Twenty minutes ago Doctor Martha Jones informed us that you would be coming soon and to direct you to briefing room three when you arrived," the secretary replied.

"She couldn't have done," the Doctor protested.

"She said you'd say that. Briefing room three," the secretary told him.

"Now you listen to me, you paper-pushing, government peon! My friend is in danger and I'm not moving until I find out that I'm getting some help getting her out of it!"

Just then Martha's voice rang out from a small machine on the secretary's desk. "Has the Doctor arrived yet?"

"Just in, Doctor Jones," the secretary responded. "He seems to think you're in some sort of trouble."

"I was. Tell him it's solved and that we've got another problem," Martha replied, "and ignore any crankiness. If he gives you any trouble, he'll have me to deal with."

The secretary looked back at the Doctor, quirked an eyebrow, and said, "Briefing. Room. Three."

The Doctor favored her with a dirty look, but allowed Ross to lead him to the specified room.

When he entered, his jaw dropped. On the other side of the room, Martha Jones was perched on the table talking to a young, blond man in cricket clothes. That man turned to face the door, and his expression was not even remotely happy.

"You thick-headed, Academy drop-out! I hope you're my last regeneration so I'll at least have senility to excuse my growing list of sins! Don't you remember even the simplest things about time travel?" demanded the blond man.

The Doctor blinked. "The two of us together should short out the time differential," he breathed in surprise.

"That is assuming that there is a time differential to be shorted out!" the blond thundered, growing in volume towards the end of his sentence.

The Doctor gave him a blank look.

"Huon radiation," the blond man said succinctly.

"Bugger me," the Doctor swore.

That's the end of this story. But explanations for everything (especially the Fifth Doctor's presence) are forthcoming in the sequel. And yes, they are explanations that make sense, I promise. : )