I’ve been trying to figure out something about Clara, as many other people do, I presume (it’s Lost all over again, when a tiny bit of anything led to enormous theories…). Until the newest episode there was nothing, but then there was the Great Intelligence in The Bells… Again.
You see, according to Tardis Data Core, the Great Intelligence is actually Yog-Sothoth himself. [link for ya] In case you don’t know anything about him (which is a crime BTW, go and read H.P. Lovecraft’s books NOW!), here’s the most important piece of information: he’s “the Gate and the Key”, the god of all time and space. He knows all and sees all.
Does it remind you of someone?
And here comes Clara. “The woman twice dead”, the woman who lived three times (at least as far as we know) and two times was somewhow linked to the Great Intelligence. It can be a coincidence of course, but if Moffat or other writers know what they’re doing with Yog-Sothoth, then there’s no place for coincidence.
Also, as for the you-know-which-forest and “I am afraid” - what could it possibly be to make the Doctor afraid? No aliens were able to do that, not even Rassilon. But what about the god of time and space, the only being more powerful than the Time Lords?
Yog-Sothoth would also be powerful enough to break the walls between universes (however, given his nature, he doesn’t have to break anything, he’d just have to reach out) and bring back Rose and Tentoo (as they are back for the anniversary). He would be able to multiply Clara for some reason. He would also be able to create circumstances which would allow the Valeyard to be “born”.