Spoiler
Alduin: Dovakhiin, the Graybeards never told you about your father...
You: They told me enough! They told me you killed him!
Alduin: No, Dovakhiin... I am your father!
You: No... No! That's impossible!
Alduin: Search your feelings! You know it be true!
You: They told me enough! They told me you killed him!
Alduin: No, Dovakhiin... I am your father!
You: No... No! That's impossible!
Alduin: Search your feelings! You know it be true!
I mean like something else un-expected coming up... perhaps a second Greymarch upon Tamriel? Perhaps an invasion from Akavir?
I was reading up on the Imperial Library out of boredom, and I eventually came to the Akavir section, which reminded me of Mysterious Akavir, and of course, Tosh Raka. Something just sort of clicked in my head then: Tosh Raka apparently became a dragon, correct? Skyrim is basically the first Elder Scrolls game to really do Dragons. Furthermore, it was stated in Mysterious Akavir that he intended to first conquer the Tsaesci, then invade Tamriel. See where I'm going with this? It's been two hundred years; if he had intentions to conquer them I think he would've acted by now. And again, this would coincidently coinside with the fact that this game is, of course, going to focus (We assume) upon Dragons. So, really, this is a just a theroy of mine that after Alduin is defeated, Tosh Raka (And maybe an army of NPC modified Khajiits) shows up and you may get to fight an unexpected true final boss.
This is of course just a possible theroy of mine, but this thread is just to see what you guys think about any possible twists or turns within the story of Skyrim... so, discuss!