G-d appeared to Moses as he had appeared to Abraham, Isaac, and Jacob. G-d has heard the cry of Israel, remembered their covenant, and will bring Israel out of Egypt.
Moses and Aaron visit Pharaoh to plead with him to release the Israelites. Pharaoh is not inclined; Aaron’s staff turns into a serpent and swallows the magic staffs of the Egyptian sorcerers.
Plagues fall upon Egypt. The water of the Nile turns to blood, the land is swarmed with frogs, lice infest all men and beasts, wild animals invade the cities, pestilence kills domestic animals, and boils cover the Egyptians. Fire and ice hail from the sky upon the land. Despite all the damage, all the plagues, all the pain, Pharaoh will not let the Israelites go.