Abram in Egypt
A famine drove Abram to Egypt, where he passed Sarai off as his sister and Pharaoh took her into his palace until God intervened.
There was a famine in the land. Abram went down into Egypt to live as a foreigner there, for the famine was severe in the land.
Genesis 12:10 (World English Bible)
Fearing the Egyptians would kill him to take his beautiful wife, Abram told a half-truth: Sarai was his half-sister (Genesis 20:12). Pharaoh took her, but God struck his house with plagues. Pharaoh rebuked Abram and sent him away with all his possessions.
It's an honest picture of a man of faith failing under pressure, and of God protecting his promise anyway.
Places
Dating notes
Ussher places this in 1921 BC, the year Abram entered Canaan, and names the pharaoh Apophis. Which pharaoh this was is not known with certainty.