The Hybrid will one day cost a billion hearts to heal it’s own. Maybe that day has passed- the Doctor, trying to get Clara back, sacrificed himself billions of times. Not killed 4 billion times because each time he was there for days before he was killed, but with his two hearts multiplied by all of the others… Maybe the Hybrids work is done? But is. He. Half. Human. I have wondered for years about this theory, even since before the 8th Doctors saying as such -but then, rule one, the Doctor Lies.
And Clara in reverse of Donna.
Also, President’s daughter. The episode made it sound almost as if when the Matrix told the Doctor of the hybrid and he ran this was the first time he ran from Gallifrey. Does this mean Susan was not his granddaughter by the President’s daughter or did I miss something and this was a different time and has something to do with Romana that I missed?