Merry Christmas! This one-shot's idea has been on my mind since I saw 'Rosa' where the Doctor stopped a time traveller from changing history. It reminded me of a certain Time Lord who dressed in a monk's habit. Oh, on that topic, I've written two stories where the Doctor is a time meddler himself. Please take a look.

For this story please leave feedback.

Krasko and the Monk.

Standing next to her new friends, the Doctor grinned as she watched Asteroid 284996 aka Rosa Parks drift through space through the TARDIS doors lazily but with a kind of grace no-one would have ever expected from something everyone would describe as a rock.

Watching the asteroid as it drifted within the belt that was gravitationally held in this solar system, the Doctor reflected on the recent adventure she'd had in Montgomery with her new friends.

She had admired and loved many humans over the centuries, but there were many moments during her long life which now spanned fourteen lives as opposed to the average thirteen every Time Lord was meant to have, but thanks to her wartime incarnation and all her subsequent lives apart from her prior life denying and ignoring the existence of that same incarnation even if it was virtually impossible, where she had to ask herself whether humanity was worth it.

She had seen how humans could react confined while they were faced with the unknown, but after witnessing for herself the violent racism in Montgomery…..

The Doctor was not blind. Her tenth incarnation had tried to be optimistic when he and Martha had been stranded in the 1960s during that mess with the Weeping Angels, but she remembered only too well how many times Martha had cried herself to sleep every night because of how extreme the racism was. Martha was a woman of the 21st century, and she and her family had endured racism all her life, but never to the same extent as black people had endured in the past. What was worse was Martha had endured it not once, but twice thanks to that mess with the Family of Blood. Her tenth self had always held Martha at arms length after that disaster with Rose (the Doctor was relieved her later lives had gotten over the blonde human - that type of attachment was just not healthy. She still wasn't sure why she had thought she "loved" Rose), but her tenth incarnation had never ignored the pain Martha had felt, he was just too incapable of helping her in case she made some big thing out of it.

The Doctor wondered how Martha would have felt about the mess with Krasko. Martha had probably grown up idolising Rosa Parks much like Yas did, she would have been disgusted by the way Krasko had tried to alter history. But she would have been shocked and disgusted with the way that man, that stranger, had slapped Ryan in the face and threatened him with hanging because he'd just picked up a glove.

Why didn't I tell them how bad things were? The Doctor asked herself irritably, feeling guilty for being so negligent that she had risked the lives of Yasmin and Ryan, and it had grown worse when they'd wondered into that cafe, and that bitch of a waitress had practically forced them out.

"Where do you think that Krasko bloke is now, Doc?" Graham asked.

The Doctor was startled by Grahams' question, and she looked at him like a startled rabbit for a second before she recovered herself. "I don't know," she replied honestly, though she made a mental note she desperately hoped to keep, "but I'm going to try to track him down. I set that time displacement weapon to send him back so far into the past there won't be any advanced technology for him to use; Krasko may come from your future, and he may have engineering and scientific knowledge that would revolutionise your century a million times over, but he doesn't have the resources to make anything to help him get back to the future."

"Are you sure that temporal displacement thingy sent him back far enough for that?" Ryan asked.

The Doctor nodded. "That weapon isn't as precise as a TARDIS or a Vortex Manipulator," she said, "but the thing is I'm not sure just how far back into the past he was sent. I'll have to check, but even if he had access to a blacksmiths' forge where he'd have metal to work from, he would need to spend years, decades, trying to find a way to escape."

"What do you think he'll do?" Yas asked in concern in case they met him again.

The Doctor shrugged. "Again, I don't know. I doubt he'd try to meddle in history again, he hasn't got any way of escaping or reaching anything worthwhile to alter. He only went back in time because he believed Rosa Park's actions ruined everything, but he couldn't outright kill her thanks to that work on his brain which stopped him killing anyone. All he could do was manipulate events so she'd never have refused Blake's order."

"Do you think he's still alive?" Graham asked. "I mean, I know what you just said, Doc, about him being stranded centuries ago from where we are now, but do you think he's trying to survive where he is?"

"Probably, but it depends on which century he's been left in. If he's somewhere like the Cretaceous period, there's no way he could survive, especially with the mass extinction event that killed the dinosaurs," the Doctor's face, already grim became even more haunted as if she were reliving some other darker memory before her expression brightened. "But anyway, you lot should be pleased; you've just seen history unfold, and you've just helped your world become a reality."

"What, you mean it's that simple? Rosa Parks had that much of an effect?" Ryan just had to ask.

Yasmin groaned. "Oh come on, Ryan, think - if it wasn't for Rosa, we would never have the opportunities we have today."

"She's right, Ryan," Graham said. "I would never have married Grace."

The Doctor had to look away at the look of pain that flashed over Ryan and Graham's faces - she would and could never forgive herself for what had happened to that kind-hearted woman.

When she looked up she found herself looking at Yasmin's face. The young woman was looking at her curiously but seriously with a haunted expression on her face. "What's wrong?" the Doctor asked.

"Krasko."

"What about him?"

"When you watch things like Star Trek everyone seems to have sorted out their own differences, but Krasko was human, right? I mean, after being on Desolation and meeting those people who didn't even know about Earth, we've come to realise aliens doesn't automatically mean tiny, big-headed and with glassy black eyes, but I'd have thought humans would have gotten over racism." By the end of Yasmin's rant, she was panting.

The Doctor sighed. She had heard this several times from various people over the years. "For the most part, humans and people who look like humans have grown beyond things like racism. But the problem is racism is ignorance, and that stays no matter what happens. Krasko is probably one of billions of like-minded people in the future who can't cope with equality, so he decided to go back in time and tried to stop the civil rights movement; some people may think Martin Luther King or Malcolm X had been responsible, but it was Rosa who started the whole thing. Krasko knew that, so he decided to alter history at a key point. Let's just be thankful the TARDIS landed us there to stop it."

"Is that what you do, travel around and stop people meddling in history?" Graham asked.

The Doctor looked at them seriously. "When my people developed time travel, we quickly realised if we changed history we could cause terrible devastation though some events cannot be altered. So yes, I do travel around to make sure history unfolds the way it does; I admit, I have altered time once or twice, but I would never alter historical events as important as Rosa Parks' role. Krasko didn't realise that if he interfered then his home time may not be what he remembered. In fact, he reminded me of one of my own people."

Graham gaped. "One of your own? But I thought you'd just said-."

"He wanted to improve history, Graham. At least that was what he had told me when I first met him after leaving our world. He believed the only way to do that was to interfere and meddle with it, just like Krasko did, only he just had a better idea of the rules though he didn't really understand them," the Doctor interrupted before she went on thoughtfully. "I don't know for sure if he'd have tried to meddle in Rosa's life, though it's possible; it's hard to tell with people like that what they'd do."

"When did you meet him?" Yas asked her.

The Doctor suddenly looked older like the barrier she used to hold back her age suddenly failed. Yasmin exchanged a quick glance with Graham and Ryan; they had all heard how the Doctor had changed her appearance from "a white-haired Scotsman" when they'd first met, and Graham and Grace had listened as she had told them how she hadn't always had the same body thanks to some process unique to her people and she had changed her entire body, but none of them knew precisely how old the Doctor was.

Looking at her now, the humans in the TARDIS could tell the Doctor was quite old, though whether she'd actually tell them Yas didn't know.

"A long time ago," the Doctor replied. "Many lifetimes ago. Oh," she suddenly looked nostalgic, "I was so young then. I used to think I knew everything because I was so young, and yet I had the body of an ancient man." She inwardly smirked as her friends looked surprised - she would really need to begin discussing regeneration and what it did, but this was not the time. "It was fifty years after I left my homeworld that I met him trying to interfere with the outcome of the Battle of Hastings. Was it the Battle of Hastings?" she suddenly asked herself before she looked around as if hoping to see the answer stencilled on one of the walls before she nodded. "Yeah, definitely the Battle of Hastings. He believed that King Harold with a few years of experience would have been a good kind and all those wars in Europe would never have happened if the Vikings were taken out of the equation."

"He disguised himself as a monk and hid inside a derelict monastery off the coast of Northumberland though he interacted with the people of a nearby village, while all the time he kept watch out for the Viking fleet. He set up a cannon on a cliff in preparation and he had a box full of neutron missiles to wipe them out; even if the explosions hadn't killed the Vikings, they would have been flash-fried by the radiation blasts."

Yasmin shared a look with her friends, horrified by the extent of the plan. Somehow it was worse than Krasko's plan though they weren't sure why that was. It could have been because it was one of the Doctor's people behind it instead of a white supremacist mass murderer.

"He told me he wanted to improve history, but while I could see the attractiveness behind making people's lives easier, I felt it would have been better to add improvements when they already had the means of doing it instead of just handing it to them on a plate," the Doctor went on and she walked back to the console. She had to get Yas, Ryan, and Graham home; after what had happened to Bill, the disgusting way Missy's previous incarnation had turned her into a Cyberman to get back at him, the last thing she wanted was for another group to pay the price for knowing her.

"I told Steven and Vicki, two people from the future much like Krasko, if the Monk had succeeded in changing history, they would never have been born," the Doctor said as she began setting the controls, hoping the TARDIS would get them back to Sheffield in the 21st century.

She hadn't meant to say that. But after they'd seen Krasko meddling with history, and they were already aware of the potential changes to their own lives if his plan had succeeded, a few more examples of what could happen wouldn't hurt.

"What do you mean?" Ryan whispered, but his voice was so low the Doctor had no idea what he was really feeling.

"Steven and Vicki were both English," the Doctor explained, "but they couldn't tell if they came from one hundred per cent Anglo-Saxon stock. If one of their ancestors was a Norman, and he died during the battle, they would never have existed. It's one thing to want to improve history, but the Monk also planned to give humanity technology way ahead of their time, including nuclear weapons. It would be a wonder if humanity didn't destroy itself before they'd become mature enough to use them."

Yasmin's eyes widened in horror as she pictured a man wearing a monk's habit just handing over a load of boxes containing nuclear bombs to a handful of men wearing medieval armour without a care in the world. The nightmare image was made worse when she saw one of the bombs taken into a massive city where it was tampered with while the monk was speaking to someone on a hill when the bomb exploded, and as the mushroom cloud rose high in the sky she saw the monk shrug his shoulders with a recklessness that Yas was disgusted with instinctively, though she guessed it was the Doctor's view on it which made her colour her judgement. But after seeing the way people treated other differently in Montgomery and how someone from the future planned to destroy all of Rosa's work, Yasmin guessed it was outrage someone would deliberately interfere.

Ryan had personally met Krasko head on. Even now his ears were ringing with the racist shit Krasko had spewed out. Like Yas, he'd thought that as humans grew over the centuries they'd become better people and things like race, creed, and colour would die out. He hadn't regretted sending Krasko back through time but he was puzzled over something.

"This monk guy, did you ever meet him again?" Graham asked before Ryan could say a word.

The Doctor looked at them sideways thoughtfully for a while. "Once or twice," she said. "The next time I met the Monk, he was trying to get revenge on me for sabotaging his TARDIS; I'd removed a component from it which caused the interior dimensions to reduce in size, but I knew he'd repair them eventually and he came after me. Unfortunately, he was forced to help another enemy who was after me at the time who had a genocidal plan for the Milky Way. I stopped them, but I once more crippled the Monk's TARDIS by removing the component it needed to direct it's travels. The Monk ended up on an ice planet from what I learnt later."

The Doctor sighed and she looked haggard. "But the Monk wouldn't let it go," she whispered, "because years later, he took a friend of mine who'd stopped travelling with me with him instead. At first, they had some fun but then it all fell apart."

"How?"

"The Monk took Lucie, that was my friend's name, to this planet where a dictator was in power - I never found out the full details - but the Monk decided to do something about it, and Lucie went along with him willingly. It's been spoken about for years that a time traveller should go back in time and kill dictators, so she probably didn't understand the full extent of the Monk's plans….. until she witnessed him arrange for the dictator's parents to be killed in an avalanche."

"Oh my god!" Yas whispered.

"Lucie forced the Monk to let her go, and he did… but she didn't realise he was once more manipulating the situation by dumping her on a moon base in your future where human colonists who were trying to terraform a planet were stopped by the awakening of a bunch of alien warriors. When she arrived I'd managed to get them out safely in a rocket, but when she appeared she sent me a message. I tried to wrangle with the crew of the rocket to let me go back, but they refused. The Monk forced us down by using his TARDIS, making it academic anyway."

The Doctor let out a noise between her teeth. "I was travelling with someone else at that time, a girl called Tamsin. She wasn't happy with my desire to go back for Lucie. She had a self-righteous attitude and believed we should have just left her there to safeguard everyone else. I'd originally had that mindset - the needs of the many outweigh the needs of the few, not the one, but I didn't believe that anymore. The Monk met her when she was off in a strop about me and my mindset, and he charmed her and took her on a trip in his TARDIS. He took her a thousand years ahead to a planet called Halcyon. The planet had a rich civilisation, but it was going to be destroyed by the same alien race that was attacking those humans because they'd be forced to head out looking for a new home. I could understand the Monk's reasoning, but he and Tamsin failed to realise the Halcyon people were a spacefaring race; there were colonies out there, their people and their way of life would survive in some form out there even if the loss of the core of their culture was a blow and a great tragedy. But if he had succeeded there's no telling what could have happened."

"I managed to stop the Monk's plan, if it had succeeded then something much worse could have happened. But Tamsin had become so taken with the Monk's philosophy she went with him. The next time I met him was on Earth in the 22nd century. He was helping another, more dangerous, alien race conquer the Earth. He'd hidden the facts from Tamsin; stupid girl, she thought the aliens were a benevolent race who were helping humanity get back on its feet."

"Why, what happened?" Graham's voice was a horrified whisper.

The Doctor took a deep breath before she decided to get it over and done with. The one good thing about this terrible story was it had happened before the Time War, so her friends had no knowledge of the Time Lords so they wouldn't feel the same loathing her people had experienced during the conflict and what Clara had let loose when she had found out what Rassilon had done after forcing her previous self into that confession dial, but it would still horrify them.

"The aliens were after a number of viruses that had been scattered in time and space," the Doctor explained, deciding not to give them the full story, never mind who the aliens were; none of it was important, and though it was a long shot she hoped she and her friends didn't run into the Daleks by accident. "They managed to retrieve one, and they decided to use it to turn an earlier defeat into a victory."

"Victory? You mean those aliens had already conquered Earth before?" Ryan asked.

The Doctor nodded. "Yes. They'd conquered Earth and they'd battered the planet down so badly it was a miracle any people survived." The moment the words were out of her mouth, she wished she could take them back, but she went on. "Don't worry - I stopped it. But thanks to the Monk, the aliens were able to re-conquer Earth. He spread the plague into Earth's atmosphere, went ahead a couple of years when it had burnt itself out, and he went along with the aliens who conquered the planet while he helped himself to the art treasures."

The Doctor's eyes closed as the memories of Tamsin's terrified face as the Daleks surrounded her, the Doctor's eighth self and the Monk while the Monk tried to persuade the Daleks to let him go resurfaced. "Eventually the Monk told me about their plans to rip out the planet's molten core, replacing it with an engine to take the planet around the universe," she said, "my friends managed to escape when the aliens attacked, but the Monk was forced to watch as Tamsin was shot down. Another pointless death. My friend….. Lucie…. she gave her life to save the human race and end the aliens' threat, and the Monk rescued me and…..someone else," the Doctor stumbled on the last part of the statement, not wanting to discuss Susan or Alex and her place in their lives, "but the Monk saved our lives."

The Doctor's expression twisted with anger. "I was furious with him; I'd worked out the Monk was the one to help the….. aliens," she said, stumbling because she had almost said the Daleks name out aloud, but she didn't want to even say their name. "I'd already guessed it was him who spread the virus into Earth's atmosphere. I sent him away. I was furious with him because he wanted to get revenge on me, but instead of keeping things between us he had to involve others. My friends, the population of Earth, and so many others, and he had been out of his depth with all of it. He hadn't known what was really going to happen. It isn't an excuse," she added seriously, "but it's true."

"Where is the Monk now?" Yas asked curiously.

"I don't know," the Doctor replied honestly. "But when we landed in America and realised history was being altered, I admit I did think of the Monk. It's likely he's out there….somewhere."

The Doctor headed for the console, and she began checking over the systems - she was trying to still work out how the console worked after spending so long with just the one console where the control systems were more logical - but her mind was no longer on Krasko, but on a man she had not seen for a long time.

Was the Monk still out there? Had he regenerated? Had the Monk regenerated into a female incarnation much like the Doctor and the Master had, or was he still male? The Doctor closed her eyes as memories came back to her; a chubby-faced man wearing a monk's habit, grinning and acting like a schoolboy as he boasted about his plan while trying to rope her first self into the scheme, the same version of the man wheedling and making deals with him, Steven and Sara and the Daleks, to a man with a moustache who poisoned Jo in order to conduct his experiments, to another version of the Monk who stupidly allied himself with the Dalek Time Controller without even thinking for one second about what he was doing.

The Doctor opened her eyes and busied herself with her work, making it clear to her friends she just wanted to be left alone while she thought about the Monk.

What do you think?