Executive producer Steven Moffat stated on Twitter last week that the episode currently shooting is Episode 7. This means that, as rumoured, River Song will feature in the mid-series finale before the show takes a break for the summer.

Speaking earlier today at the launch for ITV1’s new supernatural drama, Marchlands, Kingston commented: “I’m doing one right now actually”, when asked if she would be returning to Doctor Who beyond the opening two-parter of Series 6.