"Cheong-Chau is never idle," came the reply. "Rumour has it that there are fine fish in his net. Do you know that Men-Ching passed through here late yesterday afternoon?"
"Indeed! And where was he going?"
"He did not say."
"Some secret business," said the other. "Men-Ching is no more than the coolie of Cheong-Chau. He does all the dirty work. He runs the errands."
It was here that the voice of a third man joined in the conversation.
"I know where Men-Ching was going," said he. "I made it my business to find out. He goes to Canton to the opium den of Ah Wu, which lies near the Mohammedan Mosque. He did not leave this place till nearly ten o'clock to-night, after having smoked several pipes of opium. He is a great smoker, Men-Ching. He went down the river on a wupan that was taking a cargo of rice to Canton. The wupan calls at Sanshui, to take on board certain chests of tea."
The man who had spoken first laughed loudly.
"You know everything, Hsien-Lu," said he. "You are always prying into other people's affairs. For myself, though I wear the scarlet coat, I think it well to give Cheong-Chau as wide a berth as possible. He will have his head cut off some day. That is beyond all doubt. And on that occasion I should prefer not to accompany him. And now, good-night. I desire to sleep. The opium has made me drowsy."
After that there was silence. Frank gave them about ten minutes in which to prepare themselves for slumber. Then he got up from his couch, put on his coat and, unobserved, left the opium den.
Outside he took in a deep breath of the fresh night air, then hurried in the direction of the river. He realised that fortune had played in a remarkable manner into his hands. Men-Ching was but a few hours in front of him. He intended, if possible, to overtake the man and possess himself of the letters. He might be able to do this by stealth if he could not succeed by force. He could, at any rate, make sure that the letters reached their destination, since the lives of both his uncle and Mr Waldron depended upon their delivery into the hands of the Governor of Hong-Kong.