Doctor Who: The Newbies Guide
This is the third story in Season 25, though it takes place after the fourth story. It is the official 25th Anniversary story.
The seventh Doctor is fond of mixed metaphors and malapropisms and carries an umbrella with a question mark handle. He is more prone to plan and take proactive action against his foes than his other incarnations.
Ace (real name: Dorothy McShane) is a teenager from 1980s Perivale, London. She is interested in explosives, and has invented one called Nitro Nine. Whilst experimenting with it, she was caught up in a timestorm and ended up on the planet of Iceworld. In Dragonfire she met the Doctor and joined him on his travels. She has the habit of calling the Doctor "Professor" and sometimes using nicknames for other people she encounters.
Recurring and Historical Characters
The Cybermen originally came from the planet Mondas, a twin planet to Earth. The planet somehow left its orbit, travelling into deep space. In order to survive its people started replacing their body parts with cybernetics. Eventually they became more machine than man, removing their emotions. Now much stronger than humans they seek only to survive and convert human beings into more Cybermen. The Doctor has encountered them numerous times. In Revenge of the Cybermen, he discovered that gold dust clogs their breathing apparatus, and is fatal to them. In this story, their vulnerability to gold appears to be much stronger than that.
This story features a brief cameo appearance of Elizabeth II, the Queen of the United Kingdom (played by an impersonator). It also features real-life Jazz Musician Courtney Pine briefly appearing as himself.
It is highly recommended that you watch the extended version of this story as the broadcast version was missing a couple of important scenes.