The 36th season premiere of "Doctor Who" treated viewers to something they had never seen before in the show's 54-year history.
The Doctor's newest companion and co-star is Bill Potts, an openly gay woman.
The Doctor (who has been played by 13 different actors over the years) always has a traveling companion to keep him grounded on his adventures throughout time and space. His companions are almost always female, often young, and conventionally attractive. Their relationships are not always romantic, but as is the case in many shows featuring male and female leads, the romantic and sexual tension is always there, hovering in the subtext.