Alright first, since this is Doctor Who its practically impossible to know EVERY detail on the show. so do forgive me if something makes no sense, tell me and I'll fix it! Also, this is the 10th Doctor and after the Time War, but I'll explain what happened to the 9th regeneration soon ;)
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The Doctor and Lorelei.
Lorelei and the Doctor.
No matter how you put it, the two were always together. They had been friends since birth on the planet of Gallifrey, they went through thick and thin, but always together. The Doctor was a Time Lord, and so was Lorelei, but not completely. Lorelei was a mix of Gallifreyan and an unknown species nicknamed Inconnu. She had been created by the Time Lords to fight in wars. She had been one of a thousand created, but only Lorelei was able to outlive the new species. She had many of the same traits of a Time Lord such as Regeneration and the ability to go through space and time. But she was a fighter, while the Time Lords weren't one to physically fight, Lorelei could do both physically and vocally fight.
But the Doctor and Lorelei were inseparable, it eventually led to a romantic relationship, and an engagement. But before they could be wed, the infamous Time War began forcing the two to fight against the Dalek's together. The Doctor knew what he had to do to save all of space and time, and who would be killed, but he didn't want to risk the life of Lorelei. So he sent her to Earth for safekeeping.
But neither knew who she would meet before the Doctor could get her back into his arms.
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I need someone to play Lorelei! I was thinking either Amanda Seyfried or Annasophia Robb. Who do you guys think?