I kept wondering, How did she know, until realizing that it was also grim desperation. Well, good that it worked for one generation--Yeongjo (Sado's father) was pretty well the last to live past age 50 for the rest of the dynasty. In a very rough way, Yeongjo's "need" to start oppressing Catholics--a marker for slow disruption of centralized rule and related belief systems--is the beginning of the end of an increasingly corrupt, involuted system. I am neither pro nor anti Catholicism, in Korea or elsewhere; it's an old-ways-versus-perceived-threat thing.