Disclaimer - I own neither Doctor Who nor Stargate SG1.
Author's note - The Doctor in this story is the Unbound Doctor from Full Fathom Five, the Big Finish audio drama where the Doctor from a parallel universe believed the ends justified the means and was more than willing to commit murder if he believed it was the only way to stop evil from happening and didn't hesitate to kill anyone who'd committed evil acts and hadn't learnt from their mistakes.
Enjoy.
Playing with Bio-Weapons.
The Doctor would always be surprised by how much a group of people could be altered from the main species if they had been removed and deposited somewhere else which was far different from the environment they were used to, as opposed to them being like a handful of creatures from a rockpool that had been deposited somewhere else and merely settled into their original behaviour pattern, although there would be a few exceptions.
Although the basics of the human pattern were known throughout time and space which often refuted the ideas other races, especially humans trapped on Earth who didn't know any better prior to their 22nd century, of life being variable, the fact remained that the Goa'uld were responsible for the removal and for depositing humans on different worlds to work as slave labour while also being the fodder needed to create more Jaffa armies, as well as being used by the parasitic race as hosts.
While many of those human slaves had managed to rebel against their Goa'uld masters and shaken off the yoke of the conquest and buried the Stargates the Ancients had littered across the Milky Way centuries before, not many had been lucky and were either long since wiped out or scattered across the galaxy. But those who had managed to survive had tried to develop without the Goa'uld bothering them.
For the most part, they had adapted to their new lives, and some human cultures had used what little pieces of Goa'uld technology that had been left behind to start afresh and develop into technologically advanced cultures. For the most part, they were forgotten by their former oppressor and allowed to live their lives peacefully; and unlike humanity on Earth who had buried more than the Stargate in Egypt, they had never forgotten about their past.
The Goa'uld may have had access to space travel, but their dependency on the Stargate network made it difficult, but not impossible as the humans on Earth and who worked for Stargate Command and a few in the United States government and a few others elsewhere found out in their first year of using the gate for frequent missions after recovering the Abydos cartouche to help them chart new destination 'addresses', to get a fix on a particular world. It was because of the difficulties the Goa'uld System Lords had with finding their old territories when there was an uprising using their fleet that was the reason they had decided to focus on their other territories and just try to forget about their old ones.
Their desire to save face had allowed a few human cultures within the Milky Way to become technologically advanced, and two in the galaxy had managed to surpass the Goa'uld, which wasn't hard since the Goa'uld preferred to scavenge technology and all they had to work with were scraps left behind by the Ancients and the Furlings.
The two human races in the galaxy, barring the ones from Earth, who could pose a threat to the Goa'uld were the Aschen and the Tollans. Both races had developed technology that was a century or more ahead of Earth in development if the Earth-bound humans hadn't re-discovered the Stargate and discovered more advanced science.
The Doctor wasn't interested in the Tollan; not only had they made so many mistakes, he knew that even if he did intervene to stop Anubis from levelling their planet to rubble, but there would also still be survivors and they would eventually re-contact the humans of Earth, later on, that was recorded history. But when they did re-encounter their old 'allies' though whether or not the Earth-humans would see them as allies after what Anubis had tried to make them do or not he didn't know and frankly did not care, the Tollan would be a little wiser about not taking things at face value, but he could understand their hubristic attitude which mirrored that of the Time Lords.
No. He was more interested in the Aschen. The Doctor had learnt about the Aschen when he found a nice little timeline which had been created where SG1 had made contact with the Aschen, who had offered humanity advanced technology without the kind of fears about what the humans might use it for. The fears, which, from the Doctor's point of view had some logic to it, the Tollan had refused to offer considering how they had recklessly given some of their technology their neighbours, who'd used it in a terrible war on their own planet and didn't want anyone else to be wiped out because of an accident.
In the new timeline humanity had access to advanced teleportation technology (for them; he had studied it with the TARDIS when he had visited the timeline, which was still in existence before he had separated it from the main events within the Time Vortex; the device was on a primitive rung of the ladder when it came to other teleportation methods and technologies out there, but it was still sophisticated in other ways), and they had also made interstellar travel possible, with the Stargate being used to ferry passengers to other planets like it was an airport.
But what had really altered humanity was the number of drugs the Aschen provided, like the anti-ageing drug among other things. With access to those medical technologies, people never aged and if they suffered from something like cancer or leukaemia they only had to see an Aschen doctor and BINGO! They were cured.
But the Aschen had a sinister agenda. They wanted Earth itself, but they weren't the type of race to use weapons that would cause more damage to the planet. Instead, they were patient, dangerously patient - they preferred to use biological warfare and with the drugs they benevolently bestowed on their victims, secretly counting down how many humans were being born each year before they were ready to act while the drugs made humans infertile and unable to bear children.
He may have regenerated into a man who was unafraid to find ways to justify the means, but the Doctor did not like it when children were injured or killed, especially by an alien race who wanted a few extra orchards or planets to feed their own population.
With that in mind, the Doctor had set out to figure out a way to help SG1 stop the Aschen. It was too late for them to really stop the drugs, though there were ways around it.
The Doctor knew, sooner or later, someone would realise and would talk. But it would be difficult; the Aschen had learnt their lessons from their time conquering the Vollians. They controlled the media, and no-one had really realised, or cared, about how much power they were giving to the Aschen. Still, he had interfered. He hadn't bothered to get involved much beyond telling General Hammond about the findings and pointing him in the right direction to find the answers he'd need to get word to his old colleagues from SG1 and let them join the dots before he was killed, but he hadn't interfered with the former SG1 teams' investigation and subsequent plan to send word back in time to make sure their past selves never encountered the Aschen.
He had planned for it, and he was waiting within the TARDIS for the change in the timelines to make sure it wouldn't interact with the main events of the Time Vortex.
The timeline did change, but frustratingly the Aschen were still featured in it. Again, the Doctor had interfered by making sure SG1 discovered the rudiments of what was left of the Vollian civilisation. There was not much, but there would be enough for them to understand the dangers, and the sinister and disgusting picture became clear.
The Doctor actually smiled as he thought of the poetic way the Aschen had gotten their comeuppance by being given a Stargate address which would open up to a black hole which put paid to the number of worlds that would have been open to them otherwise. Frustratingly some of the Aschen would have survived, and they would have launched a terrifying and more powerful bioweapon which would have wiped out all life barring birds and cockroaches on Earth before devastating the rest of the galaxy, reducing the humans of Earth to a handful in a brutal war which would have ended badly regardless unless they used time travel to change the past.
The Doctor decided to save them the trouble, and he didn't have any problems on his conscience; changing history was strictly forbidden and the Time Lord laws on genocide was just as harsh, but since the humans were going to use time travel anyway it would make little difference, and truthfully the Doctor didn't really care about the genocide part since the Aschen deserved it.
He decided to use a bioweapon, deciding it would be ironic considering how the Aschen used bioweapons to render a species sterile. It was a nasty form of medicine, but it would be effective. He developed the bioweapon in the TARDIS laboratory. It was a very straightforward weapon. Geared to the genetic structure of the Aschen, it would be breathed in by the Aschen and then it would spread through the body before it activated and killed the Aschen, and there would be nothing they could do since he had programmed the virus to activate after a certain amount of time. It would remain undiscovered by the Aschen doctors since it was beyond their science, and by the time it activated virtually every Aschen should be dead, and even if some survived the humans of Earth would be the least of their priorities as they tried to rebuild their race, and if they survived then it would be unlikely they would cause problems in the future but he would remain alert in case that happened.
He could live with that. But overall the Aschen should be dead by the end of this.
As he materialised the TARDIS in the atmosphere of Aschen Prime, the last planet on his list, the Doctor hesitated for a second before he threw the virus out of the door and closed the door.
"No loose ends," he whispered.
He didn't feel particularly guilty about what he had just done; unlike with that mess with the Vervoids, the Doctor had consciously wiped out an entire race to prevent them from causing even more destruction on a scale which would spread throughout the Milky Way galaxy.
True, the Doctor would have preferred to deal with the Aschen at an earlier point of their timeline, but he knew he couldn't have done; the revelation of what they did to the races they allied themselves to had warned the Stargate Command people of the dangers of making quick alliances before they had the full facts even if it robbed them of potentially advanced technology.
Speaking of technology, in the long run, the humans of Earth wouldn't even need Aschen technology to help them deal with threats like the Goa'uld or the Wraith. Thanks to the Asgard humanity would have everything they would need, and soon with the Atlantis Expedition soon to be sent to the Pegasus galaxy new and more advanced technologies would be open to Earth.
Walking back to the console, the Doctor started setting the controls…
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