Board Thread:Skyrim/@comment-1157147-20130322022136/@comment-50.153.135.140-20150710211350

I'm assuming that Vulthuryol had been summoned before, after being placed down there as a egg, but the dragon got out of control and killed a few Dwemer, so they put him away somewhere maybe to be summoned again as a sort of super weapon, but they vanished before that ended up happening, leaving the dragon to wait for the clanging of the orb to come again.