I've been thinking about Snow Throat. The Tower of Skyrim, it's identified with High Hrothgar. What is its stone? And after the conclusion of the Oblivion Crisis officially closed off Oblivion, why do we care?
I'm starting to think that the events of Oblivion touched off a new era in the relationship between the Towers and the World, on during which the forces of the Dawn become increasingly desperate, vicious... and ultimately meet complete failure and disappear from history. Interpreted a certain way, both the Oblivion Crisis and this recent matter with Alduin appear to follow a similar pattern, previously unknown.
In Cyrodil, it was White Gold Tower, the Amulet of Kings, and the lit Dragonfires that held back destructive beings from another place. The Mythic Dawn forced the Tower "offline" by interrupting the ritual (hmm...), seeking to tear down the wall completely. Martin Septim, Dragonborn Emperor, brought this to an end by destroying the stone completely, but creating a NEW circumstance that holds the Daedra out of Mundus in a more permanent fashion. I am proposing that White Gold is not merely "offline" now... it is, today, nothing more than a tower of stone, and it doesn't have to be any more than that, not anymore.
In Skyrim, High Hrothgar was also an important location in the elimination of incredibly destructive mythic beings: the Dragons. It is presumably where Kynareth, through Parthanax, taught men to Shout, allowing them to defend themselves. It is also the location where Alduin was tossed into a time unknown, and the time-would persisted. I propose that the time-wound itself is the "stone" of Snow Throat, the Tower by which Skyrim was made safe for mortals and made mortal society possible.
When Alduin came back through, presumably the time-would closed, destroying the "stone" and placing all Skyrim, once again, in mortal danger. Alduin may not have come to eat the world, but he most certainly did come to end Nord society as we know it, and possibly end all human life... and afterlife.
But this time, Alduin wasn't cast out by well tutored students of the Way of the Voice. Rather, he was actually slain, by a Dragonborn. And so, once again through the actions of a Dragonborn, a crisis involving the return of highly destructive mythic beings was brought to a more decisive, lower maintenance end through the actions of a Dragonborn. Today, I propose, High Hrothgar is nothing more than a really high mountain... and that's all it needs to be.
Did the Covenant between Akatosh and Allesia, perhaps, prefigure a coming Covenant, a more permanent one that does not hang by a string?