It wasn't until nearly the end of DOMD that Emperor K'ang Hsi revealed that he was aware of Wai Siu Bo's being a member of the Heaven and Earth Society, but how early did the emperor actually discover this fact? His spy Fung Tzai Chung had been planted in the Heaven and Earth Society long before Wai Siu Bo joined the society, and Fung could have told the emperor almost immediately after WSB joined up. I'm under the impression that the emperor only found out shortly before he exposed WSB, but in fact, did K'ang Hsi know all along?