WARNING! THIS ARTICLE CONTAINS SPOILERS FOR THE EPISODE ‘HEAVEN SENT’
It’s safe to say there’s been no other ‘Doctor Who’ episode like ‘Heaven Sent’. It’s certainly one to watch again repeatedly to catch all the subtleties missed the previous time – although 2 billion repeat viewings to get the full flavour of the Doctor’s experience might be a bit much. I will admit though, the morning after my first viewing when there were a couple of questions still in my head, I googled for explanations before sitting down to watch the episode again. I couldn’t find an article specifically dedicated to an explanation of ‘Heaven Sent’ so I thought the thing to do would be to scratch my own explanations in the sand for anyone who can’t commit to sitting down for another 55 minutes to get answers.
What is the castle?
As seen at the end, the castle is inside the Doctor’s Confession Dial, which we can now explain as, rather than a container for confessions, a place where the owner is put inside to force confessions out of them as the only way to stop the Veil is to confess deeply-held secrets. It then rewards the captive for confessing by moving the castle to take them to a place of rest – such as a bedroom with a picture of someone they love. But then they quickly bring the Veil back to bring them out of a place of comfort, a technique matching the description of a torture chamber. The Doctor, however, finds a loophole which allows him to escape. But it, er, takes a while.
How long was the Doctor in the castle?
The reveal near the end of the episode tells us that the Doctor stays in the castle for a matter of days – at a time, that is. He explores the same rooms again and again, finding the same clues and reaching the same conclusions. In one moment he looks up at the night sky and works out the date – 7000 years since the events of ‘Face The Raven’. He is then then is fatally wounded and, resisting regeneration, the Doctor triggers the teleporter he arrived in to materialise a copy of himself kept in its system before he dies. Each subsequent copy goes through the same experiences safe for a few differences – later copies look at the stars and calculate the time passed as ‘fifty million years’, ‘600 million years’ and finally ‘2 billion years’. Assuming that the days in the castle are roughly 24 hours, let’s call each experience a week. That’s at least 52 Doctors a year, and over 2 billion years that’s a minimum of 104 billion individual experiences in the castle.
What is the Veil?
The Veil is a device used by the Confession Dial to scare the captive into confessing their secrets. It takes a particularly deep fear and gives it life so that the captive would do anything to stop it, even reveal things they never would otherwise. The Veil’s appearance is born from a childhood event the Doctor describes – seeing an old lady who had died wrapped in a shroud and covered in flies. We see it die as the Doctor makes his escape, presumably because its purpose was at an end.
Where did the clothes come from?
In the moment where the Doctor finds identical clothes to his own sopping wet ones, I assumed it was a time loop of some sort, and presumably he did too as he makes sure the clothes he has changed out of are in the same position as the ones he found. So each copy changes into the clothes the previous one left behind. By this logic, however, there would be a version of the Doctor who left his clothes for the next copy to find, but had nothing to change into, so presumably went through the rest of his experience in the castle completely starkers.
What does ‘Bird’ mean?
104 billion punches to Azbantium is the equivalent of water eroding rock, so over the many, many years the wall wore away. The Doctor uses a quote from a Brothers Grimm story to explain – a bird sharpening its beak on a diamond mountain would eventually erode it given an eternity (or at least the first second of it, as the story says). When he later triggers the arrival of the next copy, he writes the word ‘bird’ in the sand – except it isn’t sand. He writes the word in the ashes of his previous copy who burned himself to power the teleporter. The next copy figures out the reference before the ‘sand’ is blown away, and lands the next few punches before leaving the clue for HIS next copy, etc. A nice touch was showing the Doctor able to finish more of the Brothers Grimm story before the Veil catches him as it has to take more steps to reach him.
Where did the skulls come from?
Whenever the Doctor summons his next copy, he does so by attaching wires from the teleporter to his head before burning his body to give it power. The process disintegrates his body except the skull, presumably because it’s still attached to the machine. The next copy of the Doctor eventually returns to the teleporter, sees the skull that he missed the first time he was there, and takes it with him. When he’s next confronted by the Veil, the skull falls into the ocean surrounding the castle, where it joins the many other skulls of his previous copies that were dropped in the same, repeated event.
What was the writing on the wall?
When the Doctor first spots the Veil, there is writing printed on the next to him which neither he nor the camera particularly focus on. It reads the same as the Doctor’s opening monologue about something stalking you since the day you are born. We can assume it was left by the maker of the Confession Dial to explain to the captive the purpose of the Veil.
Why is the Doctor sometimes in the TARDIS?
Anyone who’s seen the ‘Sherlock’ episodes ‘Sign of Three’ and ‘His Last Vow’ will be familiar with Steven Moffat’s visual metaphors for thought processes. Here it gives life to the assertion Missy had in ‘The Witch’s Familiar’ that the Doctor’s first step in surviving peril is assuming he’s going to. So he imagines a future point where he’s survived the jump out of the castle window/encounter with the Veil/escaped the teleporter-copy loop and gotten back to the TARDIS to boast about how he escaped. These scenes show his thinking while still in the moment of peril, his brain working super-fast to work out how to survive.
How can the Doctor remember his previous experiences?
After he finds the wall and realises what’s been happening to him, the Doctor tells Clara that with that realisation comes the memory of all his previous experiences. This seems odd as each copy of the Doctor is a separate entity effectively cloned by the teleporter. But in order to reactivate it, he does attach the wires to his skull and uses his mind to power it, so that must have been when the memories transfer, to be awoken when he realises he’s been living the same days over and over again.
Where did the food come from?
The Doctor is shown eating when he describes going from one extremity of the castle to the other to give himself as much time as possible away from the Veil. We do see a kitchen just after the Doctor changes his clothes and goes to the room with the circular hole in the ground with the arrows pointing to it. There are pots and pans hung up and bottles on the shelves, so this is probably where food is stored. It would be automatically replenished, as the Confession Dial is designed to keep its captive alive until they’ve made their confession, explaining why there’s enough food to last 2 billion years.
What was the octagonal hole in the ground with the arrows?
No idea. There is a brief flashback to the Doctor seeing it when he finds the writing underground, but it’s not clear why. It could be to somehow show that it was a previous version of the Doctor who put the words there instead of them being a clue left for him by the Confession Dial, but there’s no clear explanation.