The episode will last for 45 minutes, and finishes at 8.15pm, followed by The National Lottery: Break the Safe.
The episode, co-written by Phil Ford and Steven Moffat, will air on the same day on BBC America at 9/8C.
A Dalek fleet surrounds a lone rebel ship and only the Doctor can help them now... with the Doctor facing his greatest enemy, he needs Clara by his side.
Confronted with a decision that could change the Daleks forever he is forced to examine his conscience.
Will he find the answer to the question, am I a good man?[Source: BBC]