This is the third and final part of my 'Gallifrey-trilogy' story. I would recommend you to read the previous two parts "The Rise of Gallifrey" and "The Death of River Song" but if you don't want to, or can't remember anymore, here a quick summary of what happened before:

Previously:

The Rise of Gallifrey

During the darkest hours of the Time War, the Timelords did not back away from the most dangerous weapons anymore. Scientists were dedicated to explore the world of genetic engineering and combined the power of the heart of the TARDIS with a Timelord-being. With the help of The Master's DNA and the The Rani's knowledge of chemistry, The Creator could create two genetically enhanced Time Lady twins, called The Soldier and The Warrior.

The Time War proceeded and the Timelords recognised what monsters they created. Their new soldiers began to slaughter the enemy fleets and did not even care if Timelords had to be sacrificed for their decisions. The High Council of the Timelords called back the two soldiers and brought them to court where they should be punished for their war crimes.

The soldiers did not recognise their guilt as they had been created especially for war and the court decided that their punishment shall be eternal existence on the planet Earth where they would exist multiple times in time and space and be reborn over and over again without remembering who they actually were...

Theresa Riddle was a young-recruited agent by the MI6 and on a long-time undercover mission as a criminal in San Francisco when she stumbled into an adventure with The Doctor. While travelling with him, she suddenly recognised his golden watch and opened her own one - and regained her memory: Theresa found out that her real name was The Soldier and that her regained power should bring back Gallifrey from the Time War.

All parallel consciousnesses of Theresa and her sister(s) Valentina were activated, scattered among time and space. Together with The Doctor and River, Theresa travelled back to the Time War and they created a paradox big enough to be resolved by itself. When time was rewritten, only the two sisters and the Timelord couple could remember what happened.

Theresa lived in San Francisco with her girlfriend Katie who she told her true identity. Valentina of San Francisco began to travel through time and space on her own, while her sister decided to accompany The Doctor for a while.

In the meanwhile, only few of the parallel-living incarnations of Theresa and Valentina remember who they are, among them Lieutenant Commander Riddle of the USS Enterprise in the 24th century. As all parallel Theresa's are telepathically linked, they can share thoughts, but do not necessarily have to.

Although Theresa from the Enterprise lives in the SF-Theresa's future, their times are parallel to each other.

The Death of River Song

While Theresa was travelling with The Doctor (11, hence his 13th incarnation), she recognised the pain he was going through when loosing his friend over and over again. She decided to help at least a bit and rescue his wife, the Time Lady he loves most . As a nearly omniscient being (half Timelord, half TARDIS-alike), she regenerated into River's form and replaced her during her last and The Doctor's first adventure, and died instead of him in the library. Because of Theresa's powerful abilities, she only regenerated every 13th death, while the other times, she simply wakes up like Captain Jack Harkness, who had also come in touch with too much TARDIS energy.

This story now takes place after the previous ones - seen from The Doctor's timeline. Hence, it is the 12th Doctor (14th incarnation) we meet here, after Clara (finally) left. Sherlock and Watson are post-Series 3. This story also explains The Master's return in Series 8, hence when 'The Master' is first seen, he has already been the 6th incarnation (and been blonde).

The Rani, probably not known to most of the readers, is a renegade Timelord and a chemist, having being expelled from Gallifrey after some unethical experiments. She is first seen in The Mark of the Rani, a Season 22 episode which is - in my opinion - the best serial of Season 22. The Master has always been her greatest admirer and - I assume - he is a bit in love with her, though blackmailing her in the mentioned episode to cooperation against The Doctor. The Rani, however, does not want to work with The Master and sees his re-occuring arguments with The Doctor as childish. Although she appears in one other, later serial, The Rani seen here has only experienced the Season 22 serial, and hence has met The Doctor only once (on screen) as an opponnent, while he encountered her twice before (plus the charity special episode). You don't need to know the Season 22 serial in order to understand this story.

Chapter 0

"Has she been found yet?", the General of Gallifrey asked

"No, it seems she disappeared the same day that we asked her for help...It was obvious that she would betray us. Why did the High Council agree to Rassilon's proposition?" Androgar, his most loyal assistant answered.

"Rassilon should not be in power anyway. He's regenerated several times, usually reign is only allowed for one regeneration."

"But times have changed. Tell me", he said and both men stopped walking. "Do you think she used the crack through space and time to flee this pocket universe and our planet?"

"She recognised the chance and took it. We should have never allowed her to leave prison, even to help us gaining enough power to open the crack in the first place."

"But it was the only chance to save the Doctor and hence save ourselves", the younger man answered.

"And now she's out there. And prior to her escape, she broke into the vault."

"This is just a rumor."

"It has been confirmed half an hour ago. She stole The Master's consciousness that we had kept extracted from his previous unstable body."

"Are you telling me she not only escaped our planet and universe, but now she is out there with The Master's consciousness as well?"

"Whatever she is planning, I hope the only Timelord left out there may help us."

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