In the Book of the Watchers, an Enochic apocalypse from the third century BCE, the "sons of God" of Gen 6:1-4 are accused of corrupting humankind through their teachings of metalworking, cosmetology, magic, and divination. By tracing the transformations of this motif in Second Temple, Rabbinic, and early medieval Judaism and early, late antique, and Byzantine Christianity, this book sheds light on the history of interpretation of Genesis, the changing status of Enochic literature, and the place of parabiblical texts and traditions in the interchange between Jews and Christians in Late Antiquity and the early Middle Ages.