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Silurian Doctor.

No Longer Human Looking.

Kate would never be a hundred percent sure what took place at that moment. It all happened in the proverbial blink of an eye; one minute she had been sitting in on a meeting with Osgood and several senior members of her command team, the next it all seemed blurry, and the next minute she was standing in a strange realm of red, purple, yellow, and many more colours. In front of her was a very familiar person, a tall handsome man wearing a long dark blue RAF coat.

"Hello, Jack," Kate greeted wearily.

"Hi, Kate," Jack smiled, but it was far from his usual flirtatious grin. That alone worried her, that meant something really wrong was going on, but she had already worked that out when everyone in the UNIT offices had begun to blur.

"Where are we?"

"In a protective bubble in the Time Vortex. Hard to do for most vortex manipulators, but I got a new model a while back; took years to get it, and believe me, it took years. But it's good for protecting us from the changes to history," Jack explained, "right now, somebody is changing history a long way into the past."

"And the whole of human history is changing with it," Kate paled at the implications; she had read from the old UNIT files of cases in her father's time as the British commander before the UN took greater command of the organisation, and united it internationally, moments where UNIT had to handle changes to history. The business with Reginald Styles and how a group of guerrillas from an alternate 22nd century where the Daleks had invaded the Earth had travelled back into the past to assassinate Styles because they thought he was responsible for the occupation but were in fact the cause since they'd used a powerful high explosive. The Sontaran Commander Linx who was stranded in the middle ages, who had supplied a local robber with guns certainly had the chance to alter history, but that was stopped by the Doctor and Sarah Jane Smith.

Operation Golden-Age was one of the most dangerous moments where history could have been altered. Whittaker and Grover had planned to use a fracture in time to power a time machine capable of rewinding history so a group of settlers would colonise a version of Earth centuries in the past, erasing thousands of years of history in the process.

Kate had grown up on stories like that, so she understood the dangers of changing history. There were moments where she wished she didn't, of course, but as UNIT's commander, she didn't have any option but to be prepared for this sort of thing.

"How bad is it?" She asked.

"Very. I was travelling back through time just by chance, but I wasn't heading for Earth; I was in the middle of a case where an archaeologist had broken into a Jaggaroth tomb and stolen a genetic weapon, but that's not important right now. What is important is we head back together and find out what's going on," Jack said pointedly.

"Yeah, I get that. But why bring me here?" That was one thing she couldn't understand; while she and Jack had a good working relationship, she was bemused by why he would choose her. "I mean, there are dozens of people who've got more experience with this kind of change."

"There are, but I could only bring one other person in with me; Gwen's good, but I didn't want to barge into her life if Anwen and Rhys were erased," Jack looked down at his shoes at the thought of his friends' erasure from history. "Truth be told, I only had one chance, and I chose you."

"Mm," Kate wasn't really certain about that, but she decided it didn't matter now. "How far back do you think the change goes?"

Jack checked the manipulator thoughtfully for a moment before he tapped the controls while taking care not to bring down the bubble. "I dunno. There's a massive temporal shockwave rippling through the vortex; it's not just human history that's changing, it's the entire universe."

"Earth's that important?"

"Every planet is important in some way; when we get out into space, humans will create republics, galactic empires, interstellar and intergalactic federations which will affect the future of the universe for millions of years," Jack explained.

"What about the Doctor? He's a Time Lord; isn't it his job to stop this?" Kate asked.

"First thing I checked when I had the chance, Kate. But I can't get through to the Doctor, but even if I can't the TARDIS will usually take him there to stop all of this; she has a habit of taking you to places where there's a crisis."

Kate refrained from commenting that the Doctor was taking his own sweet time clearing up the damage. "Can we go there now, see what we can do?"

"That's what I'm doing; hold onto me, Kate, this is gonna be a bumpy ride!"

"Hold it, why do you need me?" That was one thing Kate could not work out. She knew how capable she was even without her father's reputation to help, but she also knew Captain Jack was a former Time Agent from the 51st century. Okay, granted she had little idea what that meant since Jack had never really described the organisation to her in too great a detail, but she pictured him as some kind of time-travelling copper. And that was before you got into his history during the 20th century where Jack had spent decades in exile, going from one war to the next. Surely he didn't need help?

But Jack was looking seriously at her. "Kate, I don't know what's going on or even who's behind this. We know this is a serious change of history, and to be honest, while I'm here I need some kind of partner. You are not only smart, but you are also quick-witted and you think on your feet. And to be honest, you don't really have much choice, not if you want your existence intact," he added pointedly.

Kate looked down and nodded when she realised he had a serious point. "Okay," she sighed and she took hold of Jack. "Well, I'm ready when you are."

Jack triggered the Vortex Manipulator…

X

… and they ended up in some kind of jungle - there was moisture in the hot air, and there was the smell of plant life everywhere - after an exceptionally rough journey and the moment she processed where they were, Kate was unable to not think Jack had made some kind of stupid mistake. She had used teleportation from alien technology in the past but she had never ever experienced anything as rough as that.

"Oh no."

Kate sighed. That was encouraging. "What's wrong?"

"I set the Manipulator to home in on the centre of the temporal distortion as the shockwaves radiated out through the vortex. The shockwave was so powerful I needed to jump time tracks to get us into the past in the first place, but…well, look around you. We're inside the TARDIS," Jack explained in horror.

"What?" Kate lifted her head, ignoring nausea she was still feeling from the time jump and she looked around. She had been inside the Doctor's TARDIS before and she had seen enough photographs taken over the time the third and fourth Doctors had been working for UNIT to help her identify the place, but the large multisided console and the central column were unmistakable. "Yes, yes you're right. This is the TARDIS. But what's wrong with the TARDIS?"

"Look at the console. Have you seen those displays and that layout before, 'cause I have!"

Kate lifted her head and looked again at the console. Her eyes widened in horror and a chill went down her neck as she took in the console's details properly for the very first time. The console had a very organic look, like something grown but refined like those shoes Chinese women used to mold their feet in to get them into a specific shape. Kate was used to the TARDIS console being mechanical in appearance, with some components and controls looking like they came from antique shops or junkyards.

But this TARDIS console…

There was nothing mechanical about it in appearance. It looked completely and seamlessly organic in appearance, with the controls looking like genetically engineered roots for buttons and levers, and puddles of leathery black water for the display screens. Only the time rotor looked relatively unchanged, although there were differences. The rest of the room put Kate in mind of a jungle, or an enclosed greenhouse and she pulled futilely at the collar of her shirt.

But the most disturbing thing about the TARDIS console was how familiar it looked. Jack was right there, but what frightened her the most was how the console's controls brought back truly bad memories.

"The console looks Silurian," Kate said, turning to the former Time Agent. "You know the Silurians?"

Jack nodded. "Yeah, I do. I've met them a few times over the years, once when I accidentally slipped back in time to their century. I even knew a group of Silurian triplets," he added with a nostalgic grin before he shook his head. "I was there, in the 70s, when the Silurian plague hit London. I'll never forget the death toll."

Kate looked down at her feet as she remembered one of the darkest chapters of her dad's career in UNIT. The Silurian plague had been one of the worst moments in modern history but it had been virtually forgotten. What made it worse there had been so many ways it could have stopped. If they had stopped Masters from leaving the Research Centre in Derbyshire were scientists there were working on developing a nuclear reactor that converted nuclear power into pure electricity or stopped Baker from being taken into hospital, nobody would have died.

After the whole mess UNIT had changed a great deal of its remit, and after the mess with the Sea Devils, UNIT began looking for Silurian and Sea Devil shelters and set up observation posts to make sure Earth's former owners did not revive and try to destroy humanity again. Unfortunately, it didn't always work. Kate had some bad memories of the Silurian attack, and she didn't want to go through any of it ever again.

"This makes no sense," Kate shook her head to urgently shake off and exorcise those terrible memories of the Silurian invasion which went hand in hand with the Zygon mess. "Why would the TARDIS suddenly look like something straight out of a Silurian city? It makes no sense."

"No, it doesn't," Jack moved away from her and he began walking around the console to take in the changes. "I don't understand how this is possible; if a Silurian did get inside the TARDIS, they wouldn't have a clue on how to program a flight no matter how smart they are. So how can they do what they've done?"

Kate looked up, torn between surprise Jack instantly believed his theory about a Silurian being responsible for this, and curiosity about what had happened to the Doctor. "Can you work with the controls as they are?"

"Perhaps; the thing is, I don't normally deal with the Silurians, and their tech is bioengineered like you can see, but some Silurians booby-trapped their own technology so if the ancient hominids touched the controls, they'd be electrocuted or poisoned. I dunno if the console's been affected the same way," Jack said as he examined the controls with his eye and quick scans from the vortex manipulator. His expression became grim. "Well, this proves it, the TARDIS is the centre of the time anomaly."

"I'm not going to bother asking you how you got inside my ship, little apes," an unfamiliar female voice boomed although the voice sounded silky, deadly and seductive - Jack was reminded of the film noir he had watched during his time in the 20th century; this voice could give a few of the femme Fatales he'd seen and fantasised about a run for their money-making the two humans turn.

A tall Silurian woman wearing a red silk shirt and khaki coloured trousers was standing there, the clothes were clinging onto her lithe frame and emphasising her curves.

"How are you doing this?" Jack demanded - usually he would be flirting with her, using his charm to dig deep for answers but right now this was not the time. "How did you get inside the TARDIS? This technology is way beyond you?"

The Silurian woman was smiling in a way that reminded Kate of the story of the cat who took all of the cream and didn't care one little bit who knew it. But her next words startled both humans. "Oh, come on, Jack, I would have thought this was obvious. I did say this is my ship, right?"

"So?"

The look the Silurian woman sent the former Time Agent would likely have stopped a Spinosaurus from stampeding. "Oh, Jack," she hissed, "isn't it obvious? I am the Doctor!"

"What?" Kate gaped; she like everyone in UNIT were aware of regeneration, but she didn't think it could result in this. "How?"

The 'Doctor' (Jack quickly lifted up his wrist and he began scanning the Silurian woman) sighed and explained, "I was already regenerating; I travelled to different places I'd visited before in my previous life before I was attacked and infected with Silurian venom, and the Silurian physically attacked me just as the regeneration took hold. The energy spliced her entire being into me, giving me her appearance and traits."

"She's telling the truth," Jack uttered as he finished checking the Silurian woman's body through the bio scanner in the manipulator. "Two hearts…binary vascular system….residual regeneration energy. She has several Silurian physical traits, but she's more Time Lord than Silurian."

"Of course I am," the Silurian Doctor snarled, incensed.

"Why have you done this to Earth's history?" Kate interrupted, wanting to get down to business.

At once the Doctor's countenance changed, worrying both Kate and Jack at the same time when she began ranting in their faces, "You apes have been infecting Earth and the rest of the universe for centuries, so I am going to make sure you don't have that chance!"

"But you can't do that; what are you feeling right now?" Jack asked while hoping his knowledge of Time Lord minds was right even if was the most extreme case of post-regenerative trauma he knew of.

Kate hissed, "Jack, what the hell are you doing?"

Jack waved her down urgently. "Come on, Doctor. Think, you know what you're doing is affecting your senses. You know you can't change history like this!"

Kate could see that the Doctor looked a little nauseous, but otherwise, she seemed determined to ignore it. "Nice try Jack, but-," the Silurian face of the new Doctor smirked, but she broke off and she looked down at her glowing hands; Kate wondered whether this was some kind of venting for Time Lords, much like the exhaust from a car or smoke and steam from a locomotive. "What am I doing? I'm…changing history. Restac's personality's imprinting on mine and the regeneration is only making things worse," she muttered before she lifted her head, and the fanaticism both humans had seen before was now gone. Suddenly it looked like the Time Lord - Time Lady - whom they had known was back in control.

"Jack, help me," the Doctor said urgently and she headed for the console and her hands flew over the organic controls, slapping her hands onto large green pads that put Kate in mind of lily pads floating on a pond.

"Sure, what do you need?" Jack asked; Kate noticed the steely look in the former Time Agent's eyes, and she realised he might be prepared to help the Doctor, but she would need to be taken care of after this latest horror.

"Keep the TARDIS stable. Use the controls of that panel; here, let me shut off the defence mechanism so you can use it while I focus on cleaning up the mess I've caused," the Doctor was saying as she touched a control with a jab, and Jack got to work; this console was different from the one he was familiar with, but with the vortex manipulator's help he was able to get the hang of the new systems in moments.

Meanwhile, the Doctor had her eyes closed as she reached through the telepathic circuits and she made contact with the mind of her younger self - usually, this kind of time meddling was forbidden by the Laws of Time, but with time so badly distorting with history convulsing it didn't matter much. She made contact with the mind of her younger self, her mind accessing the TARDIS's temporal security systems and overriding them without any effort and she sent a strong but not fatal electrical surge into the console of her past TARDIS, sending her younger self to the ground. The surge was not designed to kill her younger self, but it would knock her out and keep her quiet.

But as she worked, the TARDIS lurched and she realised that the timelines were resetting but as she did she suddenly felt a blast of energy explode in her mind and everything went dark…

X

"Doctor?!" Jack yelled as the Doctor suddenly stiffened and she collapsed to the ground of the lurching TARDIS and he leapt over to her side at once and he started examining her.

Kate leaned over. "What happened?"

Jack shook his head. "I don't know. I think she received a shock. She's unconscious."

"Do you think she changed history back?" Kate asked.

"I think so. Feel that lurching; I think the timelines are shifting back to the way they were before the Doctor did this."

Kate was still confused about the whole regeneration into a Silurian. "Can this happen when regeneration takes place, Jack? A Time Lord's mind being merged with the personality of someone hostile, making them go against their own nature?"

Jack closed his eyes and rubbed his face as he tried to remember what he had discovered about Time Lords and regeneration over the years. "I dunno. I mean, I have heard of Time Lords who went crazy before settling down. But in this case… I'm not sure, Kate; I was dumped on a space station after I became immortal, and I never saw what happened after the Doctor regenerated. Everything I've heard is rumour or hearsay. The only thing we can do is stay here and watch over her. But you'll have to be with her most of the time."

"What, why?" Kate demanded. "I'm not a nurse."

"Yeah, and you are not a fixed point in time. The Doc's currently unstable right now, so there's no telling how she'll react when I'm here. In the meantime, I want to make sure nothing has changed."