Okay, on with it! Genesis 6.1-4; trouble coming.
When people began to multipy on the face of the Earth, and daughters were born to them, the sons of God saw that they were fair; and they took wives of themselves of all that they chose.
Then the Lord said, "My spirit shall not abide in mortals forever, for they are flesh. Their days shall be one hundred twenty years."
The Nephhilim were on the Earth in those days (and also afterward) when the sons of God went in to the daughters of humans, who bore children to them.
These were the heros of old, warriers of renown.