The BBC have released a series of videos giving some of background to making Doctor Who 911 “Heaven Sent” and some where in there there is a little bit of explanation of what it means…
Steven Moffat tells that the construct that the Doctor is stuck in is just his confession dial, “Composed of his own dreams and nightmares”. Peter Capaldi tells how it is inspired by an actual event in the Doctor’s past, when he was a child and has “grown in his subconscious”.
As to who has done this, or set-up this ever lasting place that endlessly re-sets itself, we still don’t know. The videos give more of an insight to the production.
In Doctor Who 911 “Heaven Sent” we have some nice science fiction concepts such as the transporter device. Science Fiction writers have often pondered how they might work. One idea of them is that molecules of the person are transported somehow through space. Another, used here, is that they could work by replicating someones body with the original being destroyed. I know of one science fiction story that had the original body dropped into acid!
I feel that the story works best if the whole episode is a fight in the Doctor’s mind in the process of being transported to Gallifrey.
Let’s see what the Series Finale brings next week….