Two messengers arrive at Sodom, and Lot shows them great respect and hospitality, just like Abraham did in 18:1-3.
But the rest of Sodom is not so hospitable. Basically, the people of Sodom want to sex them up.
Lot steps out of the house and asks the mob to knock it off. He offers his two virgin daughters to the mob instead.
Yep. Lot offers them with the stipulation that the mob can do with them what they please, but that the male guests are off limits.
The mob isn't happy. After all, Lot is really a foreigner in their land. Why's he judging them? That's not how it works.
They threaten to rape Lot and then the guests, but the guests grab Lot and bring him inside, blinding the men outside with a bright light so none of them can find the door.
His guests tell Lot to split with his family because they are going to take this city down. And sure enough, the Lord rains "brimstone and fire" upon Sodom and Gomorrah. Everything is wiped out: the cities, all the inhabitants (except Lot), and even what is growing in the soil.
The messenger instructed them not to look back, but Lot's wife can't resist. Consequently, she is turned into a pillar of salt. Why not?
In the morning, Abraham proceeds to the place where he earlier debated with God over the cities' fate. All he sees is that the land is sizzling. The cities did not even have ten good people.
Only Lot is innocent, and God sends Lot out remembering Abraham's principle that God should not destroy the innocent along with the guilty (recall 18:23).