There are those who say the Yazidis are heretical Muslims or renegade Christians. Others claim they are apostate Jews, or an odd Zoroastrian sect lost in the folds of history. Some insist that their caste system must have been derived from Hinduism. There is a widespread assumption that the Yazidis are an ersatz version of an original creed, a stray offshoot. Arthur disagrees. More and more it seems to him that their lineage, as rooted in the soil as the native trees, can actually be traced back to the time of the Ancient Mesopotamians.