Narcissa Malfoy

The sneering, scowling, arrogant, and ambitious dungeon set of Hogwarts are understood to pursue only the most-power hungry arts, to fall prey to the temptation of that foulest branch of Magic. One thinks they smuggle between themselves copies of Hexes Moste Foule, Blackest Blood Magic, Grimshaw Gaunt’s The Might of Darkness.

And yet Slytherin has produced and will continue to produce a very different sort indeed. It had produced those who, though appearing to possess all the advantages of blood and power, have abandoned those for love; those who seem sinister and slimy, but conceal within themselves great courage; those who might toss aside blood principles and alliances with one wild lie; even those whose wealth and family ties, such powerful armor against the world, mean nothing when balanced against regard for a house-elf or beloved nephew.

And so we must conclude that Slytherin house is not always as it seems, and that the strength of those dungeon-dwellers lies not in Darkness and crude power, but in another, subtler, far more cunning sort of magic.