There was once a woman with no sense of propriety, who had an extramarital affair and was divorced over it. Her name stank, and she was afraid of what people would say, so she did not dare go out and spent her days at home cursing Heaven and Earth.

Later her mind changed altogether. She went so far as to "converse" with a big rat that lived in the house, and fed it, and gave it a name — Big Treasure.

Human beings all deserved to die, in her view. Rats were the treasures.

That woman was Ma Jintu.

When the apocalypse came, Ma Jintu and the big rat she kept mutated at the same time, and because there was a great deal of food stored in the cellar at home, she and the rat came through the apocalyptic storm. Once the storm stopped Ma Jintu came out of the cellar, met some survivors, joined them, and began a new life.

Everything might have gone well from there. The end of the world had come, the past was past, and nobody knew about her filthy reputation.

She could start again.

But she was found out by the other survivors — she was in contact with a pack of mutated big rats, and taking the food the human survivors had gathered to give to them. Once she was caught, Ma Jintu meant to kill to silence them, and failed. That was very nearly the death of her at the other survivors' hands.

Afterwards she won their sympathy purely by acting the part, and traded her body to attach herself to the leader of the little band.

As the ratmen grew and spread, that little band had to move up into the hills to keep away from the rats and the floods and the other disasters, and there was too little food and clothing, and life was hard. None of which suited Ma Jintu. And on one occasion in particular, when she was beaten by the band's leader for hiding a bag of potato chips, Ma Jintu went altogether mad.

She called…