The episode was first broadcast on 12 January 2014, on BBC One, and written by Steven Moffat, directed by Nick Hurran with music composed by Michael Price and David Arnold.
The episode was first broadcast on 12 January 2014. This was on BBC One. The episode was first written by Steven Moffat. Steven Moffat was directed by Nick Hurran with music. This music was composed by Michael Price. This music was composed by David Arnold.