When Doctor Who first premiered in 1963 there was a main cast of four people. The Doctor, the teenage Susan, and her teachers Barbara and Ian. While much is made of how The Doctor regenerates when he dies, to be played by a new actor every few years, the companions change too. In fact, all three of The Doctor's original companions left the show in the second season, well before Hartnell was replaced by Patrick Troughton. While current Doctor Peter Capaldi is leaving at the end of the upcoming season, he needs a new companion to start the season off with.
At the end of the last season of Doctor Who, his latest companion Clara erased all memories of herself from The Doctor's mind and went traveling through time and space without him. One thing the revival of the show has made very clear is that when he is alone, the Doctor is not his best self. He needs someone at his side to help guide his conscience and his heart. An earlier trailer for season 10 introduced that companion as Bill, played by relative newcomer Pearl Mackie.
And now there is a new trailer (see above), focusing on Bill and her feelings about The Doctor. Companions are not just anyone, they have to share The Doctor's love of adventure and danger. They tend to leave their lives, planets, and loved ones behind in order to risk their lives by joining him in the TARDIS to time travel, as well as visit other planets. The Doctor tends to throw himself and his companions into danger everywhere they go, generally to help people and save the day, so he is very selective of who he chooses to join him. This trailer certainly shows that Bill shares the eagerness and curiosity that tend to make up his roster of companions.
The trailer does not show much new footage, instead focusing on Bill's narration about The Doctor. She describes meeting him in stages:
"The first time you meet him, he's funny. The second time, he's amazing! The third time, you realize he's the most dangerous man in the universe. He says he's a man of peace, but he walks in war."
After that, Bill turns the focus onto herself, talking about how much she enjoys traveling with him, despite the dangers. The whole time she, The Doctor, and his recent companion Nardole (Matt Lucas) - who has been seen in the last two Christmas specials- are moving forward together.
The three of them walk through what looks like a library while Bill narrates. Around them, lightening flashes and books explode. They are walking towards... something. This something seems like it is trying to kill them, so it's a pretty normal day for The Doctor and his friends in the trailer. There is no indication whether this thing facing off with the group in the trailer will appear on the show as well.
Bill seems to embody everything the Doctor looks for in his companions. A willingness to face danger, excitement at the thought of adventure, and a certain admiration for him. Her enthusiasm is contagious and makes for the potential start to an exciting tenth season.
Doctor Who returns to BBC America on Saturday, April 15th at 9.