Howling:The Voice in the TARDIS

In "the Pandorica Opens" back when the cracks were the big threat of the day, River is trapped on an exploding TARDIS. During this point, a voice warns "Silence Will Fall" just before everything gets kind of hectic. No one's made mention of that voice, not really in universe or out since then. Now that we've seen what might be the end of the Prophesy or at least the beginning of it, I think it bears wondering. WHO was that voice? Was it the Great Intelligence, falling back through the Doctor's Time Stream? Was it something else? Or will possible be left alone and never mentioned again? Vohn exel ☎  06:49, June 13, 2013 (UTC)