Eoin Colfer said this quote
“ how does she know it's the right room?' wondered Descant.Oh, I don't know; mabye it's the magical red glow coming from the doorway, or perhaps it's the deafening howl of the temporal winds.' said Mervall. Descant nodded.'You could be right, brother. And don't think I don't know sarcasm when I hear it. ”