Bill Potts was the final companion of the Twelfth Doctor. She shared a teacher-student relationship with him similar to that of Leela and Gabby Gonzalez, albeit on more official circumstances.

When she first encountered the Doctor, Bill was working as a canteen assistant at St Luke's University, seemingly destined for an unprivileged life. When free from work, she attended some of the Doctor's lectures at the university. The Doctor saw her unfulfilled potential and invited her for a series of personal tutoring sessions.