The Doctor gets a Stetson (and a gun!), and finds himself the reluctant Sheriff of a Western town under siege by a relentless cyborg, who goes by the name of the Gunslinger.But who is he and what does he want? The answer seems to lie with the mysterious Kahler-Jex, an alien doctor (yes another one!) whose initial appearance is hiding a dark secret.
Writer - Toby Whithouse
Executive producers - Steven Moffat and Caroline Skinner
Producer - Marcus Wilson
Director - Saul Metzstein
The episode will be broadcast at 7.35pm - 8.20pm on Saturday 15th September 2012 on BBC One. It is scheduled against ITV1's Red or Black? and the first ten minutes of The X Factor.
(Source: BBC Media Centre)