The story of the watchers

DR. MIRYAM T. BRAND: The Benei Elohim, the Watchers, and the Origins of Evil. According to the non-biblical book of Enoch, Genesis 6 tells of angels who bring sin to humanity, causing the Flood as well as sin and disease in the present. (TheTorah.com). A good discussion of the story of the fall of the watchers according to the Book of the Watchers (1 Enoch 1-36).