"So," Narcissa said, "as we all know, the Yule Ball is being held in three days’ time, and it will be a golden opportunity for reconnaissance against the enemy. Real reconnaissance, not whatever is gleaned from dusty corners and half-heard gossip. Naturally, Draco, Pansy and Blaise all have invitations. It is imperative that Hermione be there, so she will be travelling in the guise of Pansy’s lady’s maid."