Evelyn Smythe

Evelyn Smythe (later Evelyn Rossiter) was an accomplished academic, rather closer to the end of her long career than the beginning of it. Depending on her audience, she was known as Professor Smythe, Doctor Smythe or just plain Evelyn. As a professor of history, she was naturally most interested in the TARDIS' time travel capabilities. She occasionally found that theories to which she had devoted much of her career were invalidated by actually examining history first-hand.

Her history with the Doctor was complicated, as it involved a period of time where she was the Sixth Doctor's active companion, and several visits long after she had departed. Accounts of her life, especially after her initial journeys in the TARDIS, have occasionally conflicted, suggesting some degree of meddling with her time stream.

Biography
When Evelyn met the Doctor she was a History lecturer at Sheffield Hallam University. She was of interest to the Doctor due to her being the temporal nexus point that he arrived in search of. He took her back to 1554 to try to save her life. With this done she insisted that she join the Doctor on his travels as she couldn't pass up the opportunity to travel through time (BFA: The Marian Conspiracy).

Travelling with the Doctor, she met The Brigadier, Charles Darwin and the Silurians (BFA: The Spectre of Lanyon Moor / Bloodtide). She was also present during the Etra Prime incident and the Dalek invasion of Gallifrey, where she had her eye print scanned into the Eye of Harmony (BFA: The Apocalypse Element).

In 2003 London, she befriended a young waitress named Cassie and when Cassie was turned into a vampire by Nimrod, she and the Doctor set out to find a cure (BFA: Project:Twilight). By the time they returned, Cassie had been brainwashed by The Forge and it was only through persuasion by Evelyn that she could be returned to her original personality. However, before she could escape in the TARDIS with the Doctor and Evelyn, Nimrod killed her. This devastated Evelyn (BFA: Project Lazarus).

Cassie's death and the Doctor's inability to save her put great strain on Evelyn's relationship with him and caused her to need some time away from him. During this time, on the planet Vilag, Evelyn grew close to a man named Rossiter. However, she felt that she couldn't leave the Doctor for him (BFA: Arrangements for War).

Evelyn was suffering from a heart condition when she met the Doctor, something she never told him in case he refused to let her travel with him anymore (BFA: Project Lazarus). Eventually on a return trip to Vilag, Evelyn decided to leave the Doctor and marry Rossiter. The Doctor reacted badly to this and treated Evelyn badly, rather than say goodbye properly. She had hoped the Doctor would attend her wedding and give her away, but he never turned up. She had surgery to cure her heart condition, however, in actuality, the surgery had used Killoran blood to disguise the problem, and also caused headaches and short temper.

Two years later, the Doctor arrived with his companion Mel to visit Evelyn, who had been having problems with her step-daughter Sofia's ideologies. Evelyn and Mel are kidnapped soon after as political prisoners. It is soon established that although the activists, who had injected Evelyn with Killoran DNA, knew Sofia, she was not involved with their plot. The Doctor and Sofia worked together to save Evelyn's life, and although her heart condition was still not cured, Evelyn was happy and she and the Doctor made their peace at the renewing of Evelyn and Rossiter's vows (BFA: Thicker Than Water).

An alternate view
According to another account, Evelyn may not have ended her initial travels with the Sixth Doctor on Vilag, but on Earth. In this timeline, she was returned to Earth a decade prior to her departure, forcing her to live her life in isolation from her relations, her career and her home. She feared she might run into her "younger self" and thus risk the cruel end afforded by the Blinovitch Limitation Effect. She was rescued from this paradox by the Sixth Doctor and Mel — the latter of whom she had not yet met. Upon the conclusion of an adventure with the pair, she asked to be taken home via the Eye of Orion. (PDA: Instruments of Darkness)

Behind the scenes
Evelyn is a particularly tricky character for the casual fan of Big Finish productions to follow, because her stories were released more-or-less chronologically only to Thicker Than Water.

After this story, however, additional adventures have been told which are set much closer to The Marian Conspiracy than Thicker Than Water. Moreover, her appearance in the PDAs was part of a plan to make her a regular companion in the Past Doctor Adventures series and predates the way her character was written out of the audio series.

However, the novel range was cancelled before additional Evelyn stories could be penned, leaving her exit and subsequent first meeting with Mel at odds with the way both events were depicted in audio. Nevertheless, it is curious that Gary Russell, who wrote Instruments of Darkness, allowed this contradiction, since he was the producer of Thicker. Russell later somewhat addressed the issue in PDA: Spiral Scratch, in which it is suggested, though not clearly delineated, that the novel range and the audio range occur in two separate realities.

Personality
to be added