The episode had 6.61 million viewers after a week of recordings - a rise of 1.63 million on the initial viewing figure of 4.98 million. While it's a lower figure than Cold War, it's worth noting that Hide's initial viewing figures were dented by sun and a clash with Britain's Got Talent.
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]