Additionally, Capaldi finds himself wandering into the very shack he played in as a child and of course, as Doctor Eleven, saved Gallifrey with the help of Doctor Ten, The War Doctor and Bad Wolf Girl. Reminiscing past doctors was a perfect addition to Capaldi's second series. Something felt homely about it. Complete.
Although these two destinations are the big noted references to past Doctors and series, there are so many more throughout the episode, including knocking in multiples of four, a reference to The Master and perhaps a hint at a later discussed subject: The Hybrid.
When on Gallifrey, The Doctor drops a spoon when asked to 'drop your weapons'. A spoon of course being the weapon he chose to defeat Robin Hood.
And possibly the saddest reference is that of The Doctor explaining that he had once wiped the memories of a past companion, referring of course to Donna Noble.
I am however disappointed that so much time has been wasted saying goodbye to Clara. Face The Raven was a great episode and one that opened many doors for the story line, so why was it necessary to drag out Clara's goodbye for two more episodes? This was a great ending. A new one. Our first companion to die since the 2005 rebirth of the series. Having a dead companion was a little exciting. (Yes I know, technically she's still dead ... )
After bringing Clara back to life between a single heart beat, we all cringed at The Doctor's reluctance to let go of this tired companion.
However, in a wonderful twist, Clara the waitress is the real deal and ends up along side Ashildr. The pair intend to return a borrowed TARDIS to Gallifrey only after they have taken the long way around. I can't help but fear that this just leaves Clara open to visit over and over again. Ashildr, sure, but Clara ... please Moffatt, give us a break.
Ashildr still has so much to offer The Doctor. Billions of years lived with the curse of immortality will make for fantastic future cameos and conversation. Plus Maisie Williams is killing it, let's be honest.
When approached by council members of Gallifrey, they ask The Doctor what he wants. His answer is simply, The President, who he blames solely for The Time War.
Although this should be such an important part of the series, even The Doctor returning to Gallifrey is overshadowed by Clara.
Of course we all just assumed this meant a hybrid consisting of half Time Lord half Dalek, yet when face to face with Ashildr, her prediction to The Doctor is that he and Clara have become one, thus creating a hybrid being, part Time Lord, part Human, consistent with how big Clara has become and possibly thanks to Missy.
So really, this was the point of the episode. Clara Oswald. Oswin. The Impossible Girl. Her time is finally up and she's ready to run, but more importantly, it was time for The Doctor to realise that he needed to let her go. He couldn't keep saving her or he would live out the prophecy that he, as half of the Hybrid, would eventually have too much power.
One more thing - goodbye Ray Bans, hello ultimate Sonic Screwdriver.