Patricia McBride

 was a professor of anthropology in Sheffield. According to Hebe Harrison, she was the most celebrated professor on campus.

Biography
She encountered the Sixth Doctor, Melanie Bush and Hebe whilst they were investigating the Mindless Institute and assisted them in derailing the plot orchestrated by it's leading benefactor, Mr Betterment. (AUDIO: The Mindless Ones)

Some months later, she called in the Doctor, Mel and Hebe from the Emit Institute in Sweden to look into their claims that they can rewind a person's time. After uncovering a crashed ship beneath the facility, she helped the Doctor repair Killian Holm's machine after she destroyed it so he could undo the damage. After the institute was destroyed, Patricia asked for a trip into the future. (AUDIO: Reverse Engineering)

Bringing her to the 26th century, Patricia immediately demanded to return home. After a collision in the time vortex brings them back to the 21st century, the Doctor called out Patricia, having realised long before that her reaction to the future was because of entirely bigoted views she possessed about the disabled and the unalike, considering the people of the future and those of the present to be simply "wrong". Disgusted, the Doctor sent her away and Hebe, after hearing these views for herself, was equally sickened and shunned her. Confronted by her hatred everywhere she went, she ran into Khavûl and is made under duress to help him find the Drornidian Oubliette. After Khavûl was defeated, Patricia scuttled off and used Khavûl's abandoned time suit, adopting the username Purity, to alter the world to her own image, making Hebe disappear from existence in the process. (AUDIO: Chronomancer)

Personality
Patricia was possessing of a sharp wit and a sharp tongue and was not taken to suffering fools lightly. She appeared to take most abnormal situations in her stride, accepting the alien nature of the Mindless Institute and Killian Holm's time machine fairly swiftly. (AUDIO: The Mindless Ones, Reverse Engineering)

However, for all her positive attributes, Patricia was greatly bigoted and withheld a great dislike for those with 'flaws'; she claimed to be tolerant of the disabled or homosexuals, but in reality believed that they were simply something to put up with because they couldn't be changed and told Hebe that she'd hoped that by the 26th century, they'd have fixed people "like [Hebe]", claims which both Hebe and the Doctor were respectively distraught and appalled by. (AUDIO: Chronomancer)

Behind the scenes
There are similarities that can be drawn between Patricia and Adam Mitchell in their brief acquaintances with the Doctor, such as how they each recieved only two trips in the TARDIS before they were kicked out. Unlike Adam, however, who was dismissed for bad behaviour, (TV: The Long Game) Patricia is the first companion to earn the Doctor's ire through attitude rather than actions, the Doctor having been turned irrevocably against her by her own predudices and discriminatory beliefs.

A comparison could be made to the version of Elizabeth Klein who travelled with the Seventh Doctor prior to AUDIO: The Architects of History, an unrepentant nazi with equally discriminatory views; however, she was brought into the Doctor's company more on account of her anomolous existence than her political ideals.