The story
Lut believed in Ibrahim when a whole empire did not, and migrated with him (29:26). He was then sent to cities whose people pioneered a transgression no nation before them had committed, and added highway robbery and open evil in their gatherings to it. Lut's position was that of every reformer alone in a hostile town: no clan to shield him, guests he could not protect, and a wife whose loyalty was with the city.
The crisis came disguised as hospitality. Angels in the form of handsome young men arrived at his door, and the town came running. 'This is a distressing day,' he said (11:77), offering the path of purity and being mocked for it. Then the guests unveiled: we are messengers of your Lord; they will never reach you. Travel with your family in the night, and let none of you look back (11:81).
At dawn the cities were lifted and overturned, and stones of layered clay rained down, 'marked in the presence of your Lord' (11:83). His wife, who chose the people over the prophet, was counted with them; the Qur'an names her with Nuh's wife as the eternal proof that nearness to a righteous man saves no one without faith of her own (66:10). The believers walked out with the dawn.