The episode had 6.5 million viewers after a week of recordings, a rise of 1.61 million viewers on the initial viewing figure of 4.89 million. It's another drop from the previous episode, but the timeshift is in line with that of Cold War and Hide.
The figure does not include those watching on iPlayer - as usual, Doctor Who was number one on the catch-up service for roughly 48 hours after the episode.
The episode's placing in the weekly figures will be revealed tomorrow.
[Source: Doctor Who Online]