A man does not need to be a wizard to know truth from falsehood, not if he has eyes. You need only learn to read a face. Look at the eyes. The mouth. The muscles here, at the corners of the jaw, and here, where the neck joins the shoulders.
A Feast for Crows: A Song of Ice and Fire: Book Four (ed. Bantam, 2005) - ISBN: 9780553900323