Team Israelite threatens to unleash locusts on Egypt if Pharaoh continues to be a meanie. Pharaoh's advisers tell him to release the Israelites, and so Pharaoh asks Moses how many Israelites Moses and Aaron intend to take into the wilderness.
Moses and Aaron tell Pharaoh that they're taking everyone.
Pharaoh laughs out loud, and tells Moses to get lost.
Bad movie, Pharaoh.
Locusts devour every green thing in Egypt: "Nothing green was left, no tree, no plant in the field, in all the land of Egypt" (10:15).
Pharaoh says he'll let everyone go if the locusts go, so Moses and God lift the plague. God again hardens Pharaoh's heart, and he reneges on his promise again.
Next up, God unleashes Plague #9, a darkness that covers all of Egypt. This isn't normal darkness. God describes it as "a darkness that can be felt" (10:21). Yikes.
Pharaoh again tells the people to go, but asks Moses to leave the Israelite livestock. After all, the Egyptians' animals are all dead. Moses tells Pharaoh that that isn't cool, and Pharaoh gets super annoyed. He tells Moses that if he, Pharaoh, ever sees Moses again, he'll kill him.