The series introduces Pearl Mackie as Bill Potts, and also features Matt Lucas as Nardole. Michelle Gomez and John Simm return as their respective incarnations of the Master. The main story arc for the first half of the series revolves around the Doctor and Nardole occupying themselves at a university while they guard an underground vault containing Missy. Missy later travels with the team in the TARDIS, and eventually partners with her previous incarnation as they battle a Cyberman onslaught.

The series is the first to star Peter Capaldi as the Twelfth Doctor and Jenna Coleman as his companion, Clara Oswald. Also playing a major recurring role in the series is Samuel Anderson as Danny Pink, Clara's boyfriend. The main story arc revolves around a mysterious woman called Missy (portrayed by Michelle Gomez), who is often seen welcoming people who have died throughout the series to the "Promised Land", a place that serves as an apparent afterlife to deceased characters.

Now that the Doctor and Clara have established a dynamic as a partnership of equals, they’re relishing the fun and thrills that all of space and time has to offer. Tangling with ghosts, Vikings and the ultimate evil of the Daleks, they embark on their biggest adventures yet. Missy is back to plague the Doctor once more, the Zygons inspire fear as they shape-shift into human clones, and a new arrival moves in cosmic ways.

原 Doctor Who Confidential（2005），现有Doctor Who Extra（2014- ），同译为神秘博士幕后揭秘。每集10分钟到到13分钟不等。