Tamzin Outhwaite (reported last roundup) has also now been confirmed for the episode, and will be joined by Warwick Davis, whose sci-fi/fantasy career includes playing Wicket in Return of the Jedi, the titular role in Willow and the Leprechaun films, and Professor Flitwick/Griphook in the Harry Potter films. On television he has most recently been seen as "himself" in Life's Too Short.
The two are joined by Jason Watkins, who is also no stranger to sci-fi/fantasy, having played the vampire leader Herrick in Being Human; other credits include Lark Rise To Candleford, Little Dorrit, Psychoville, and Dirk Gently, and he can currently be seen as Gavin in Sky's Trollied.
Steven Moffat said:
Cybermen were always the monsters that scared me the most! Not just because they were an awesome military force, but because sometimes they could be sleek and silver and right behind you without you even knowing. And with one of the all-time classic monsters returning, and a script from one of our finest novelists, it's no surprise we have attracted such stellar names as Tamzin, Jason and Warwick.
The episode is directed by Stephen Woolfenden, with the guest stars described as "a band of misfits on a mysterious planet..."
The writer himself has been busy with rewrites of the script, teasing away on Twitter. As reported last week on the Wednesday he said: "Amazing hectic couple of days & stressed Doctor Who post-table-read rewrite in progress. On BBC legal advice Lampwick is no more.«". On Thursday, he continued: "back on Doctor Who script. Only 5 pages to trim before dawn.« They start shooting it on Wednesday. They need the script now.« There. It is FOUR pages shorter than it was this morning. It has been sent to the BBC. And I am going to bed.«" Finally, on Friday: "I believe that we've just locked my Dr Who script. I probably won't have to write it again until we need new ADR dialogue once it's edited.«" - to which executive producer Caroline Skinner retorted: "Ha ha!! A locked script is an alien concept on Doctor Who.... :-)«"
On this morning's announcement, he added: "I saw my first Cybermen watching Moonbase, as Jamie thought the Piper was coming for him (scary). Then Tomb of the Cybermen terrified me.«". And on his version of them being scary? "I hope so.«"