Disclaimer - I don't own Doctor Who or Pacific Rim.

Author's note - This story's Doctor is the one played and voiced by David Collings in the amazing Unbound audio drama "Full Fathom Five," set in a parallel universe where the Doctor believed the ends justified the means. This is the start of a small series of oneshots where the Unbound Full Fathom Five Doctor travels to different continuities and sorts out problems, sometimes doing things fans won't expect the Doctor to do.

Enjoy!

Ending the Precursors.

He wished he had anticipated this before it had actually happened, though by then it had nearly been far too late, hopefully, after spending a while travelling up and down the pocket timeline, he would end the Precursors before they really appeared and sent their Kaiju to destroy the human race.

As he worked over the TARDIS console, the Doctor lifted his head and nodded in quiet satisfaction over how things had turned out ever since he had discovered the portal leading into the ante verse. In many ways, this 'doorway' into the ante verse had been easy for the TARDIS to find since the scanners were attuned to trace and locate that kind of opening.

But what made him even more satisfied was the knowledge he was going to stop the Precursors from leaving their world and entering into N-Space, remembering from his lessons at the Academy there were numerous worlds which had been colonised and destroyed by the locust-like aliens over the aeons though their activities were stopped fairly early on and since then no other breach had opened up again.

Until now.

Only it wouldn't have happened if the Time War had never occurred, the Doctor thought to himself grimly before he pushed those thoughts to the side, deeming them irrelevant for now, though he had to acknowledge without the Time Lords around to prevent this type of invasion taking place, he would have to expect strange things happening to the cosmos now, and the Precursors could mean an omen for things to come.

He had heard of the Precursors, of course - there was a required course at the Prydonian Academy about races from different transdimensional realms which the Time Lord's had taught in order to cement the knowledge of the responsibilities they as a people had to ensure some races never appeared in N-space; the acquisitive nature of the aliens was bad enough, and usually the Time Lords wouldn't interfere, but due to the strange effects their portals had over time and space, and how they shared many of the characteristics of rip-engines in that they tore holes through the fabric of the universe, affecting reality and twisting it around like a pretzel because, thanks to their transdimensional nature, they were immune to the effects of historical change, the Time Lords had made it their duty to attune the Web of Time to block out the opening of the portals as they formed.

For many centuries the Precursors had tried to exit their universe and migrate into N-space, but the Web of Time had always prevented them whenever the Time Lords had detected a potential opening which they closed immediately.

Of course, with the Time Lords….gone, and only himself around to clean up any mess that cropped up, the Precursors had taken advantage of the absence of the Time Lords to establish a footing on Earth. When the Breach opened, it had created a fairly potent pocket timeline which would only come into existence if allowed to continue.

In the pocket timeline, the monsters the Precursors used, named "kaiju" by the humans after the mythical Japanese monsters, would launch a devastating attack on San Francisco, on the 13th of August, 2013, completely changing history as it attacked. The Kaiju, small and less powerful than later variants, though still a threat, killed millions even after the British and American armies joined forces and fought against the monster for six long, gruelling days, but in the end due to the lack of real effect, they decided to drop a tactical nuclear weapon on the Kaiju, and while the creature was killed, it had destroyed three cities, and resulted in the deaths of thousands of people.

And on and on it would go, and it wasn't until the human race banded together and built colossal robots controlled by pilots that were neurologically able to control them and share the strain, that the Kaiju were fought back, though the robots, named Jaegers by their builders, gradually lost their edge as the Kaiju began to evolve.

In the end events would come to a head when Raleigh Beckett, Mako Mori, and Stacker Pentacost were able to stop the Kaiju, resulting in Beckett and Mori taking their Jaeger into the other universe, and destroying the Precursors, though some would survive…No, it was best to stop the Precursors and their Kaiju foot-soldiers before they destroyed too much.

It was funny; ever since his first incarnation where he realised the ends justified the means, he would have tried to state the human race could have done with a bit of toughening up, and if a few million of them died during the process, what of it? Unfortunately, that was no longer true now; he had far greater things to consider nowadays. The disappearance of the Time Lords, of the stability they brought to the universe, was one of them, and he was now forced to make decisions that would be beneficial for all concerned even if some would consider the way he did things as chilling, and sinister.

For a moment the Doctor thought about everything he had seen in that little pocket timeline he'd seen. While he admired what the human race had done during the war - banding together, working towards the goal of survival in the face of the Kaiju attacks, building the first jaegers only to discover they were in an arms race against their monstrous enemies, which became more powerful and became stronger and more cunning compared to the ones they had fought in the past while they tried, and failed, to destroy the Breach the Kaiju came through from their reality. He grimaced when he thought about the disastrous "wall of life" program; while in theory it was a good project which would have held the Kaiju off in the long run, surely the government of that point of the timeline's history were aware of how the Kaiju became stronger with each new generation, what if the Kaiju's masters developed a new strain of Kaiju that had the ability to fly over the wall? But then again no government really had much common sense. He had even travelled forwards into the humans' future and witnessed the resurgence of the Precursors who had sent along a new strain of Kaiju into the real universe, only to be stopped.

It was too dangerous for the Precursors to continue.

While the Doctor had to admit to himself he would be taking the potential lives of those who fought against the Kaiju, he didn't let it bother him that much; they were only a few people compared to the big picture, and the Doctor had no intention of letting the Breach become bigger and more unstable for the Precursor's timeline to unfold which would have more unstable effects on the timeline.

However, he couldn't just walk away in the belief humanity could do with a shakedown since the Precursor's actions were changing history, and the Doctor was still a Time Lord. He had his duty to history to make sure it unfolded correctly.

Even if he felt the ends justified the means, in this case making humanity grow up and becoming united against a powerful, relentless foe, the Precursors were too dangerous to allow into N-Space, and the effects they were having on time already with opening the Breach had the potential to grow out of control.

He had no desire for the Breach that was in the process of opening to widen any more than it was, soon it would be large enough for the Precursors to send in the toxic giant monsters they'd created in order to destroy all life on Earth. The Doctor stood upright and he pressed the button which would send the TARDIS passing through the Breach, thankful his ship was able to do it since ordinarily the Precursors had programmed their portals to not accept anything passing through the entrances unless it was their bioweapons, but it was still a very shaky ride into the anteverse.

The shaking stopped after a few moments, which gave the Doctor plenty of time to get ready. He switched on the scanner and studied the vista of the kaleidoscopic colours as they blended across the barren wasteland. The Doctor studied the image over the scanner screen, seeing the image of the lake or a sea in the distance of what could only be described as a city, though the Doctor had no intention of studying or exploring it.

Without thinking about the moral implications of the consequences, the Doctor walked to the telepathic circuits, and he triggered the Delta Wave he had spent the last few days

He moved the scanner slowly around, and he caught sight of the creature the Precursors were already preparing to start the invasion off. It wasn't particularly big considering the Doctor had seen his own fair share of monstrous creatures over the centuries, but it was large enough to pose a major threat to the Earth since they wouldn't have a clue how to stop it, though they would use extreme methods to destroy the Kaiju.

Walking over to the telepathic circuits he had modified, the Doctor triggered the Delta Wave he had spent the last few days preparing. One the scanner he watched as the wave ripped through the pocket universe, burning through the minds of the Precursors. He watched as they collectively clutched their heads and collapsed as the wave, augmented by the power of the TARDIS, killed them.

The wave had a stronger effect on the Kaiju; because of its size and complexity, the giant creature actually needed two brains in order to function properly, and over the scanner, he heard the roars of pain from the creature before it died. When he was sure the Precursors were gone, the Doctor set to work on the controls. Within moments he was finished, and he began to time loop the ante verse.

He would have preferred having a way to properly collapse this pocket universe, but it possessed a nature similar to the Land of Fiction making it hard for him to properly dismantle since he didn't have Gallifrey's resources to make it possible, so this was the best he had.

When the Doctor was finished with the time loop, he reset the controls to take him out of the anteverse, and as the TARDIS finally exited the Breach he got to work on sealing it. As the TARDIS sealed off the portal knocked into the universe, the Doctor reflected on his plan, knowing it had worked; the timeline where Beckett and Mori had detonated Gipsy Danger's nuclear power plant had only killed a small percentage of the Precursors and collapsed the Breach, but some of the aliens had survived. By using a Delta Wave and a time loop, the Doctor knew he had brought an end to them.

At last, the Breach was finally closed and the TARDIS restored the local time to how it had been before the portal opened, the Doctor checked the controls to see if there was anything else he needed to do…

Please leave feedback.

Until the next time...