Rassilon scowled. This was not unusual for him, but this was for unusual reasons.

Gallifrey's greatest supercomputer, the Matrix was built from the mixture of brains of former presidents (some not entirely voluntarily or post-death, Rassilon admitted to himself, pushing the laser knife to one side) and fresh neurons grown by the computer itself. It was self-aware, knew all the history of the universe the Time Lords themselves knew and had communications links directly embedded in the brains of all living Presidents, thus updated continuously about the universe and the deepest, darkest secrets of the Time Lords themselves.

It was programmed to predict past and future events. Very important if you want to document all of reality but have finite resources. You simply look at the bits of the universe that don't match the forecast and record the discrepancies.

It would never be perfect, but it was good enough to anticipate and mitigate threats, understand every language in the universe - including ones never before encountered, plot the general paths of civilizations and above all identify events that were fixed in time. Meddling, to limit risks, couldn't change those so you had to know where they were.

"In the Dark Times, nobody worried too much about such things. Oh, those were the days!" Rassilon thought to himself.

His concern revolved around a forgotten piece of datum extracted from the Matrix, hundreds of years ago. Re-running the validator, it showed the information was still correct, the prediction had not changed. No matter how Earth's history was distorted, humans from Earth would grow to rival Gallifrey. It was a fixed point.

This was not good. It wasn't that Rassilon was prejudiced, he regarded everyone as lesser on an equal basis, but humans were singularly annoying and having them gain access to time travel, singularity control and other forms of immense power was a threat to Gallifrey he couldn't just ignore.

The Time Lords tried moving the planet but even that didn't work so they deleted that change. Powerful is bad, powerful with a grudge is worse.

The data just didn't match observation, though. The Time Lords would have encountered such humans, but none had. Even The Doctor had only encountered humans deceived into thinking they had invented time travel, whereas all they had were gimmicks the Daleks had secretly inserted actual time travel systems into, creating a psychological weapon they could use to enhance their terror.

Even at the end of the universe, humans had no sign of what the Matrix categorically stated must be there.

With all the new information and updates The Doctor continually provided the Matrix with, through the neural interface in him, surely the Matrix must have resolved whatever glitch it had! But it hadn't. The fixed point remained, undisturbed by events or by knowing humanity's future.

Even so, the statement was vague. Unusually vague. The more Rassilon tried to pin down details, the more elusive they became. Nor did it give an enlightening answer as to why, or on what basis the forecast was made, saying only that what was will be.

This would require thought. He was, technically, part of the Matrix himself. Had been since being shut up in the tower. He could create new bodies by invading the brood tanks. Because birth rates were very low, population levels were stabilized synthetically. This was necessary as he sometimes needed to act personally rather than by injecting ideas into others via the neural link.

This time, it was necessary because the Matrix refused to give answers. Something limited it. He had to be free of that limit if he wanted to work round it.

A new body would take too much time. He wanted answers now. He found that a highly intelligent technician had been using the Matrix illicitly for data analysis. He was going to be relieved of his duties after his next connection. Perfect! A good brain in a person nobody will miss. Ideal for the purpose. Unlikely to be many questions, when the brain fries after departing, either.

He remembered with a shudder as to how he had used this trick to enter a parallel universe with the entity calling itself Zagreus. He had broken out of a time loop by withdrawing to the Matrix. It had pushed the connection to the limit and he had never been completely sure just how intact he remained. He was sure he used to be subtler, though as he was synthetically regenerating, it might just be the usual mangling of the mind.

The confiscation of the brain didn't take long. A little crampt in places, but very usable. The technician was in the Matrix, so hadn't been home to defend it.

As he still had access to the Matrix, he instructed it to perform a search on anything The Doctor knew that was unique about humans that might be relevant.

After his arrest and expulsion from the city into the wilderness, he was able to relax. Nobody out here had the means or knowledge to detect his presence in the body of another and nobody inside had any interest. Not that dissimilar to how he had organized the tower. Potential threats were somewhere else concerned with someone else. Well, until he got caught, but even then he was the real victor because they failed.

The neural link he had ensured was installed hummed with activity, as data from the Matrix computations flooded into his brain.

Humans could operate the TARDIS without authorization? Interesting. Those controls are isomorphic, they only respond to one form. Had The Doctor disabled that?

Humans could also interact with the Eye of Harmony. That security could not be bypassed. It required countless biometrics, including brainwaves and genetics, to line up. That should not be possible.

The next bit of information stumped him further. Parasites are almost always species-specific. How could a parasite affect a Time Lord and a human?

This was not making any sense. It got worse when he was told that a human barbarian was living in the citadel and was genetically compatible with the Time Lords but only just. From the perspective of the primitive, archaic classification system of Earth, they were nominally the same species.

No, that isn't possible!

The Doctor's biometric scan, used to locate and communicate with him, showed ancient traces of human DNA.

It took three days for the fit of anger to pass. But then he hit on a possible answer. The prediction could be made to work. It would require breaking into Gallifrey's distant past, violating various locks he had created and breaking countless laws some of which he had written.

But as he had created the locks, he naturally had the key. As his body was an outlaw, well, breaking more laws wouldn't hurt.

The idea was distasteful to him, but the alternatives were worse. If he could use Gallifreyan synthetic biology to create an artificial cross-breed between a human and a primitive Gallifreyan destined to evolve into modern Gallifreyans, the descendants under human terminology would be human as they don't distinguish or categorize beyond that for general purposes. If their ancestors were human, they're human. Even if no human DNA remains.

Humans would therefore become equal to Gallifreyans because they really would be equal, in the human sense.

This would require creating a suitable subset. Regular humans were unacceptable, barbaric. He needed people who could imagine something like the Matrix, who could conceive of the mathematics necessary for the analysis, who had the imagination to think beyond four dimensional topologies, who would someday learn to engineer stars.

Most humans lacked the mind necessary.

But how to extract them?

A game, perhaps. Games are good. The prize, though, was a one-way trip into a fetid ancient swamp on Gallifrey. Briefly, as they were not needed once the psychometrics and genetics are extracted.

It took a while, but it seemed foolproof. Inject some ideas into The Doctor, who rarely notices unless it's blatant. These ideas end up in the heads of suitable people across human history. Very subtle ideas, enough to end up as stories but no more, nudging their minds in a suitable direction and hinting at physical locations where deeper mysteries can be found if you know how to look. However, the Game of Rassilon is never fair and many psychological traps were placed to crush those he deemed unsuitable with their own minds.

It took many Gallifreyan years to set up, but finally everything was in place. Good, the body wasn't able to handle this workload for much longer. Now, all he had to do was unlock the past and get a synthetic biology lab established.

This was not that much harder. He was a part of the Matrix, so had access to every lock as they were all computerized and linked in. He didn't need a whole lab, he just needed a device for synthesizing one. All that was left was to walk in, steal the element then steal a time capsule.

If an old man with his granddaughter could do it, why shouldn't he?

Wait. The Doctor can create a lab? Couldn't he be persuaded to go back?

Rassilon shook his head. No, far too moral to go around blending people, particularly in fetid swamps, where deadly lifeforms are everywhere.

A few hours later, his time, but around twenty five million years earlier by Gallifreyan standards, he found himself in said swamps.

In front of him, an old man and a young girl were setting up some equipment. The old man noticed Rassilon.

"Well come along, come along! Do come over and help me and Susan set these things up."

Rassilon blinked. This was unexpected and disturbing, given The Doctor's attitudes. The Doctor should not have been here, should not have had access, was not invited by him!

"Well?" Queried The Doctor. "I haven't got all day!"

"I was not..."

"Expecting us? Understand I do this only because it is a fixed point in time. This history cannot otherwise be history, not one line of it. Furthermore, I believe Fenric is involved and manipulating us all. No-one else can generate that kind of time storm."

Rassilon looked uncertain. To have done all he had done as part of somebody else's game was not acceptable. "Tell me."

"The places on Earth Fenric has manipulated the most speak the vulgar proto-Gallifreyan of this time. This was not my doing, yours or by chance. I do not approve of being manipulated, so as this event must occur, it will occur on my terms. Or would you prefer Fenric rule Gallifrey rather than just manipulate the occasional individual? Hmmm? How much do we concede to this monstrous individual?"

Rassilon sighed. The first incarnation of The Doctor, grandson of The Other, was not much easier to argue with than an asteroid. Arguably harder, as asteroids can't regenerate. You had two choices, agree or be crushed. Rassilon felt a measure of pride in the Hammer of Gallifrey, but also a lot of irritation. Nonetheless, working against The Doctor wouldn't work and if Fenric was involved, as one of the Great Powers, it was going to take a lot to regenerate.

Working together, the lab constructors were put into action. It would take a few hundred years, but that was ok.

A proto-Gallifreyan approached. "So, it is ready?"

The Doctor turned. "Fenric, I assume. It is preparing itself, but we can't stand around here for that length of time!"

Fenric smiled. "Rassilon is inhabiting a borrowed body. If he releases it to me, I will take care of the rest."

"And what happens to the humans afterwards? I want guarantees they will come to no harm!"

Fenric paused. "You are not in a position to bargain. Neither am I, if the cycle is to complete. They will survive and blend into the hybrid naturally. That comes not from guarantees but what is necessary."

The Doctor nodded. "If that is the best you can do, it will do."

Fenric turned to Rassilon. As he did so, Rassilon's centre of locus returned to the Matrix.

A quick scan showed the technician as exiled, system components as stolen with the technician as the suspect as he was detected on internal monitors. Rassilon thought for a bit, then forged a record showing a lab being grown, with nearby life-signs, in a fairly empty area. Explosions shortly after indicated the imaginary lab was destroyed. To have done nothing would have invited unwanted investigators. This might have killed a few outsiders or savages, but that's it.

From afar, Fenric smiled. Rassilon as as oblivious as the rest.