In the China in the 50's, members of a university English Department react in different ways to the new version of China that sprung up with Mao after WWII.
Baptism here is a translation of the Chinese title "Xizao", which means "bath" and was used (according to the Introduction) "to designate ...the 'Three Anti Campaign' of 1951 ... directed against corruption, waste and obstructionial bureaucratism", which targeted "bureaucrats nad managers, as well as all former members of 'bourgeois classes,' businessmen, professionals, and, as in this novel, intellectuals."
I found the reading a little difficult, because it is apparently a close translation of the Chinese, which (as a Chinese friend who was writing her book about that time once told me) has a very different was of expressing things, so it is unusual and sometimes frustrating to read. I hadn't read a Chinese novel in a while, so I'd forgotten how it is.
But I expect it gives an excellent picture of how life was for people like me if I'd lived in China then!