let me tell you guys something that has been on my mind ever since heaven sent aired, and it makes me unable to think about anything else going on in my life.
remember when we were all fantasising about 12 and Clara dying together? I mean, 12 regenerating in the same time Clara dies, because they’re just made for each other, and 12 is totally her Doctor? But it was impossible because Peter just came on the show and none of us want him to leave any time soon.
WAIT A SECOND?.. IT ACTUALLY HAPPENED.
Think about the first time the Doctor died in Heaven Sent, the first day he arrived. The first time he saw the Veil and all these rooms. He didn’t know if his plan would work, he couldn’t be sure if the teleport machine would copy him or not. But if he didn’t take the chance, he was going to die in ‘Room 12′ without having tried. So he climbed up the stairs, etc, and burned himself. It worked. Now, think of the first copy that died. He actually died, you know? The first copy, who didn’t remember he punched the wall before, who was the first skull, who painted Clara. He died without the memories of his other punches to that wall because he didn’t have any. That death was maybe IT. The Doctor’s death.
His last words were: ‘How long can I keep doing this, Clara? Burning the old me, to make a new one?’ And then, the mind-TARDIS shut down. He died a few hours after Clara died.. :))