The Jordan plains, where both cities thrived, were the dominion of Lot (Abraham's nephew), given to him at the same time god gave Canaan to his uncle. But, where Canaan seems to contain mostly harmless (or possibly just very dull) people, Jordan attracted a different kind of customer, their extravagant behaviour culminating in the twin cities of Sodom and Gomorrah, ostensibly dens of every sin imaginable (their only recorded "errant" behaviour however being a certain tolerance of homosexuals; that doesn't sound so bad to me).
After announcing his plans to Abraham, god sends two angels to Lot (who lives in Sodom, but apparently steers clear of its manifold forbidden delights, despite being the official regent) to warn him of the impending doom. He welcomes them as guests in his house. During dinner, a bunch of locals drops by and asks the angels to come out (of the closet?), that they may "know" them (bible babytalk for sex). Lot reasonably refuses (although in all fairness he should have let his guests decide for themselves; maybe they would have fancied a quick round of hide-the-sausage), but to appease the horny citizens, he offers them his two virgin daughters instead. Seriously. (Good thing we've got the bible, otherwise where would our morals be?!) The men, spurning his generous offer, remain ardently desirous of the angels (to some men, it's just not the same with a girl, virgin or not) and try to force their way in, at which point the angels strike them with blindness and prudely resolve to destroy the city next morning. At daybreak, they duly wreak their havoc and terminate the frolics in a most spectacular (and possibly vindictive) fashion. Lot & co, who fled in the early hours, are saved, but Lot's wife - despite the angels' dire warnings - looks back on the road (Orpheus again) and is instantly transformed into a "pillar of salt". Curiouser and curiouser, said Alice.
Now it gets really weird. As their mother is dead, Lot's virgin daughters decide to rape their father "to preserve his seed" (a new wife or even a concubine would also have done the trick, but as a storytelling device this was already employed for uncle Abe in the preceding chapter; presumably our writer wanted to spice up things a bit). To this extent they drug him, sleep with him (one after the other! What are you thinking, you dirty pervert, this isn't some smutty prepornographic trashy De Sade novel, but serious history!), conceive and both have a son, Moab and Ben-Ammi, who will both father a whole tribe in due time. Now one would expect outrage and a go(o)dly amount of smiting here, but to my utter surprise, there is not a single word of complaint from god, or the author for that matter (least of all from Lot himself); sleeping with your daughter/mother apparently being considered normal behaviour in those days (we can't even explain it psychologically as the girls' revenge for their dad's casual offering them to strangers as sex slaves). It'd spell BIG trouble for the vice squad were we to adopt these extremely dubious old testament morals... but have no fear, brethren, it's perfectly safe and instructive for your daughters to read this, as it is the word of god. Just don't let them watch Winnie the Pooh, as a talking and exhibitionist (no trousers! that dirty ragamuffin) bear might seriously disturb vulnerable & impressionable young souls (This actually was a hot item in some Polish backwater hicksville recently. First that drooling & demented pope, and now censoring Winnie - what is wrong with you guys? Copernicus was one of you, don't insult his memory). Just don't try this at home, kids; you might get dad in a lot of trouble.