Dr Joseph Brenner was the third GP at St John’s medical practice at the time of Margot’s disappearance. Brenner is now deceased but according to Dr. Gupta, Brenner was a bully and “a very difficult man.” ¹  Not only was he “openly hostile” toward Margot and despised her feminist outlook, but he also didn’t appear to like women in general and held some fairly misogynistic views^.2

According to Gupta, Brenner “thought a woman’s place was at home with her children, and Margot leaving a baby at home and coming back out to work full time, he disapproved of that. Team meetings were very uncomfortable. He’d wait for Margot to start talking and then talk over her, very loudly.” ³

Brenner was also said to be a drug addict, addicted to prescription painkillers. ⁴

“A doctor couldn’t get away with it these days, but he over-ordered them in massive quantities. Kept them in a locked cupboard in his consulting room.” ⁵

^{1-3: Troubled Blood, Chapter 10
4: Troubled Blood, Chapters 10 & 20
5: Troubled Blood, Chapter 10}