|So far, the mystery here is about a letter... (Source)|
Chapter 8 (CLH finally found a clue)
Chor Lau-heung dove into Tay-bing Lake, pursued by the hypnotised Fell Cut. Here we learn again that Chor tai-gor was an excellent swimmer and diver (duh, his house was a boat!), and he was very fast and agile in the water. CLH almost effortlessly immobilised Fell Cut underwater and brought him back to the lake shore. CLH then dove back to the lake and pursued the harpist, who turned out to be a white-robed monk playing the zither on a small boat. The monk didn’t seem to realise that his zither had a lethal effect to Fell Cut. The monk was none other than Biau-ceng Bu-hoa, the monk CLH saw in Chapter 3 (Bu-hoa = flowerless). The monk recognized CLH despite the latter’s disguise. Giving up, CLH unmasked himself.
Chor tai-gor then explained to Bu-hoa how three people had recognized him today. The first one was the monk himself, the second one was Fell Cut, and the third one the killer. Bu-hoa threw away his zither into the lake upon hearing Fell Cut’s name for the latter was a murderer, hence Bu-hoa’s zither has been tainted (for Fell Cut had heard its melody). Bu-hoa later discussed the killer’s Jinsut; that it originated in Arab and was brought to Japan via the Mainland. CLH returned to the lakeshore, installed Yat Dim-hung safely on the branch of a large tree, and returned to Kilam. He reintroduced himself properly as CLH to Leng Chiu-hun (who just woke up with a prostitute sleeping in his bed – gosh…). Leng reported that he heard of a stranger monk in town (named Thian-ing-cu) who wore a long thin blade as a weapon.