Peter Capaldi’s run as the Doctor ends the way it began four years ago: during the annual Christmas episode. This time he meets his original self who also isn’t willing to change. They realize they have to face their destinies.

SPOILERS BELOW

Change is always difficult to accept, though it can provide some exciting new possibilities. This is what’s happening as the Doctor will become a woman. Before that happens, the 12th Doctor and the original must accept that it is time for both to change.  If they are scared of being forgotten, that won’t happen either. Peter Capaldi made his Doctor unforgettable. That’s the same with the First Doctor, who will always be around because three men have played him.

Both Time Lords learn change is inevitable, and can be a beginning. It’s not exactly a problem that could end the universe, but to them it’s almost like that.

The episode begins in October 1966, when the First Doctor (aka One) lands in the South Pole and will soon meet the Cybermen for the first time. It even recreates the “Have you no emotions” scene with David Bradley as One, and his final moments just before he regenerates.

The BBC made an animated version of this scene. Notice Polly says he disappeared at some point. This fits into the episode’s time line.

Then the 12th Doctor (aka Twelve) and One meet. They are both puzzled to see each other, and One can’t believe he’s meeting his future self. Throughout the episode, One is very skeptical about his future form, and doesn’t even know what a Sonic Screwdriver is (that will happen in 1968). Like his second form, One does not like how the TARDIS changed. He compares it to a French restaurant. He prefers his TARDIS, which isn’t so fancy but works. Bradley does a great job recreating the original Time Lord, with just a hint of Walder Frey.

Their refusal to change suddenly stops time, including the impending death of a British captain (Mark Gatiss) in Ypres in 1914. He winds up near where the two Doctors are. This is because a glass woman reports a time line error, and now has to fix it. The captain is stunned by what he sees, and that World War I isn’t going to end all wars after all. Blame Twelve for giving him that spoiler (nice tip of the hat to River Song).

The glass girl wants the soldier in exchange for someone else. It turns out to be Bill Potts (Pearl Mackie), who insists to Twelve it’s really her. It sure seems that way when she tells One they both have experience with women.

Both Doctors think they can identify the glass girl (Nikki Amuka-Bird), so they’ll have to go to the Weapon Forges of Vallengard at the center of the universe. Some strange creatures are crawling around. Twelve meets with Rusty, also known as the Dalek he and Clara had to fix in “Into the Dalek“. Those creatures, by the way, are Daleks without their armor. Twelve figures out the Daleks’ Mind Hive could help him. It reveals the glass girl is modeled after a professor from the year five billion and 12. She’s part of the Testimony Foundation, which collects the memories of those who are about to die. They are able to recreate anyone in a glass vessel with those memories.

It’s not really an evil idea. The fact both Doctors don’t want to change is causing the crisis.

It’s also revealed Bill is really her memories in a glass form. She is interested in One, and why he ran away from Gallifrey. He says he had been fascinated by good and evil. He wondered how a balance could be established if evil has a better chance at winning logically. Bill suggests maybe someone is responsible for that, namely the Doctor. He also admits he is scared of regenerating, because he thought he would live and die in the same body.  It’s soon revealed Bill is not the real one, but her memories in a glass girl. She still tells One he is amazing and should never forget that. That’s interesting because you wonder if that’s from Bill or the glass girl imitating her.

It’s soon time to bring the Captain back to Ypres to meet his fate. He asks the Doctors to look after his family every once in a while, and they agree. In fact, they do better than that. The Captain is returned just as both German and Allied soldiers sing “Silent Night.” It’s the famous Christmas Truce of 1914, and the Captain is spared for a while. While he will forget meeting the Doctors, he’ll never forget how he almost was killed in Ypres.

The soldier’s name? Archibald Hamish……..Lethbridge-Stewart.

That’s only the beginning. While One heads back to his proper time line and his regeneration, Twelve talks to “Bill”. She says she is still the real Bill Potts even if it’s just memories under glass. She proves it by bringing back Clara Oswald (Jenna Coleman)…

Wise move, since she and Ashildr have their own TARDIS. They’re bound to cross paths again.

Nardole (Matt Lucas) is also brought back. While Twelve appreciates seeing them again, he warns the Testimony Foundation and its memories under glass is that if it ever tries to get his testimony, it would shatter them. He compares his life to an empty battleground, where they are now. He is still grateful to see old friends again.

Finally, the Twelfth Doctor gives his farewell speech, directed at his new form. It’s quite a change to when Clara got advice on how to handle him… from the previous incarnation.

Jokes aside from Twitter about “women drivers” and how some still say a female Time Lady won’t be accepted, how will she get out of this predicament?
She is the Doctor. She will find a way.

Still, Thirteen knows Capaldi will be a hard act to follow, although following Tom Baker was tough for Peter Davison, too.

Change always happens, because it will lead to something new.

Your thoughts?  Comment below or on the @Whedonopolis Facebook page.