As revealed in Doctor Who Magazine the episode, written by Mark Gatiss, will be an ‘under siege’ story featuring ‘a volume of water’ – which could confirm earlier rumours of the episode being set on a submarine.
With so many toys to play with Director Mackinnon understandably loved every minute of it:
“Without a doubt, if ever there were a team effort that has made an episode work, it was that one. Just the safety elements alone, with water flowing around… The gaffers, and the Electrical Department, and the practical effects guys, they were all on top of that the entire time… Also, we had to remember that there was electrical circuitry on show.
“All that had to be shifted to 12 volts to make it safe. And there was steam, and smoke, and explosions, and guns, and everything that makes directing Doctor Who fun. I had the time of my life. And then there’s ‘the creature’ as well.”
Obviously, Mackinnon isn’t confirming the identity of the creature, but says that it is ‘really scary’ and will feature CGI elements:
Because of the environment that Mark put his creature in, there was all sorts of texture around that’s natural to the environment… I had the creature stomping through water. I shot some of it in slow-mo, to make it look even more impressive. The results are magnificent. If that’s hard work, I’ll have some more of it, thank you very much.