Emily Winter

Emily Winter, a film actress in 1920s-era Hollywood, travelled with the Tenth Doctor as his companion after an incident in which her mind was taken over. (IDW: Silver Scream) The Doctor took her on as a companion, when she was brought to his trial, because she was saved by the Doctor, even though her death was a fixed points in time. (IDW: Fugitive) Formerly a meek and mild actress, following this event she became hardened, with violent tendencies. She insisted the Doctor give her a weapon. He refused. (IDW: Tesseract)

Emily continued to travel with the Doctor, even after Matthew Finnegan had left with the Advocate. (IDW: Don't Step on the Grass) They travelled and had adventures together for a short while, including one where the Doctor met Barnaby Edwards, a man who would be his companion in the future (from the Doctor's perspective). (IDW: Old Friend)

After having an adventure on a planet, where she helped defeat the Advocate, and met Torchwood operative, Annabella Primavera before she died. So she decided to take her place on Earth (since Annabella's continued existence on Earth was a fixed point). Therefore, she left the TARDIS to take up this new live, as well as discovering Archie Maplin and eventually setting up United Actors in Hollywood, leading to the events of her first adventure with the Doctor. (IDW: Final Sacrifice)

Behind the scenes

 * Emily's behaviour, starting in Tesseract, is reminiscent of Ace from the TV series.