Good news, everyone! Richard E. Grant returns as the Great Intelligence!
Also, Clara’s whole story is more or less explained inside of five minutes.
So, after this whole series of episodes for the Eleventh Doctor’s third…wait, this one has been kinda messed up. The first half was all about Amy and Rory moving on. Then Clara showed up, like, three or four times, and now we’re trying to figure out the Impossible Girl.
Never mind all that, though. The Great Intelligence is up to something, and that means the Doctor…is not consulted when Madame Vastra makes a conference call through the subconscious of herself, Jenny, Strax, River, and Clara. Why not other companions since there’s time travel involved already? I don’t know. Stop asking questions. Wonder instead why the episode opened with Clara following different Doctors and even talking to the First.
But then Jenny disappears, possibly dying, because the Great Intelligence and his Whisper Men, and that means Clara in the present and maybe River in the future (she’s unreliable) need to both get the Doctor to the planet Trenzalore and keep him far away from it because that’s where the Doctor’s grave is. The Doctor must never go there.
The Doctor totally goes there to save his friends with River advising Clara in an image supposedly only Clara can see and hear…wait, when did Clara become a Quantum Leap character?
Actually…that totally explains everything. See, the Intelligence wants to get to the Doctor’s grave (it’s in a giant TARDIS because when the Doctor dies, the “bigger on the inside” part stops and the TARDIS gets to the size it should be) because Time Lords don’t leave corpses when they die. They leave rips in space-time that can be accessed at great risk to other beings and that the Doctor should stay away from because it would also contain the Doctor’s future, and even a time traveler shouldn’t know that.
What does all this have to do with Quantum Leap? Simple. The Great Intelligence decided to go into the Doctor’s timeline and turn all the Doctor’s victories into defeats, causing stars to wink out of existence, Jenny to die, and Strax to turn evil until Vastra killed him herself. That means Clara has to follow and do the opposite, essentially splintering into many different lifetimes, each one there to help the Doctor, often unseen. She advised the First which TARDIS to take, and the other two times she died was also her but that’s that.
And then the Doctor, after revealing he could see and hear River the whole time, goes in to save her past all those other Doctors, sometimes with Clara or the Intelligence added digitally so-so to old episodes. Clara is found, but there’s one other figure in there. The one who is also the Doctor but who betrayed everything the Doctor stood for. The Doctor says to ignore that guy while he and Clara exit to the reformed timeline.
Oh, yeah, and that other guy was John Hurt as the War Doctor.
Not a bad set-up for the 50th anniversary, even if it did basically make Clara into Dr. Sam Beckett.