Vaeira - Sh'vi'i
Oh, Hail.
For the seventh plague, G-d had Moshe reach towards the sky, triggering a miraculous hail storm throughout Egypt. Huge hail stones fell, with lightning flashing among them. Any person or animal that dared venture outside during the hail was killed by it. It also smashed the trees and the crops, though the Jews in Goshen were once again spared.
In a panic, Pharaoh sent for Moshe and Aharon. "Okay, I admit it," he said, "this is all my fault. You guys are right. Just make it stop and I'll let the Jews go!"
"Sigh. Okay."
Moshe went out and prayed to G-d. The hail immediately stopped; the hail that was already falling was suspended in mid-air. (It finally made it to the ground in Joshua chapter 10 - see Talmud Brachos 54b.)
And, of course, Pharaoh again reneged on his end of the bargain.