The BBC has released the official story synopsis for the first episode of the new season of Doctor Who.

Written by showrunner Steven Moffat, ‘The Magician’s Apprentice’ will air on Saturday 19 September on BBC One.

The synopsis reads: “Where is the Doctor? When the skies of Earth are frozen by a mysterious alien force, Clara needs her friend. But where is the Doctor, and what is he hiding from?

“As past deeds come back to haunt him, old enemies will come face-to-face, and for the Doctor and Clara survival seems impossible.”

The full guest cast for the episode is listed as Michelle Gomez, Jemma Redgrave, Kelly Hunter, Clare Higgins, Jaye Griffiths, Harki Bhambra, Daniel Hoffmann-Gill, Joey Price, Aaron Neil, India Ria Amarteifio, Dasharn Anderson, Demi Papaminas, Jami Reid-Quarrell, Benjamin Cawley, Stefan Adegbola, Shin-Fei Chen, Lucy Newman-Williams, Barnaby Edwards, Nicholas Pegg and Jonathon Ojinnaka.

Steven Moffat has described the two-part story which opens Season 9 as “a blockbuster”, teasing: “…it’s like starting with a finale, and having a big, grand, movie-sized story, as opposed to a 45-minute story.”

> Buy Season 8 on DVD on Amazon.

> Buy Season 8 on Blu-ray on Amazon.

Season 9 has been filming in Cardiff since January.

> Here’s everything we know about Season 9 so far.

Are you looking forward to ‘The Magician’s Apprentice’? Let us know below…