Am I the only one seeing a reference, or a counterimitation of sorts, to Moria here? Dumbledore opening the gate, pondering it, finding it laughably simple (although in very different ways to the Tolkien version); then the connection to fire, and then death (falling). It does not follow it as a pattern, but there are some similarities that struck me there. Of course, Dumbledore actually dies, never to return. And the similarities accentuate the difference, I think. Still, I thought it worth mentioning.