We were so familiar with the city by this time that we often went out without Kalliboas or any other attendant, but up to the present, save on one occasion, it had always been by day. That one exception was a week or two before Poyning's accident. Where he went I don't know, but he told me next day--I was abed and asleep before he came back--that he had been out to see the valley by moonlight. Now, on the first night after his recovery, I noticed he had again left the house by himself. The same thing happened on the following night, and once or twice again afterwards. I began to get uneasy. I was still sore, I suppose, over the wigging he'd let me in for by foolishly flying over the city, but there was more in it than that. For some time past I had been conscious of a change in Stephen Poyning. That overlay of "exquisiteness" the boy had had when we brought him out of China was pretty well all rubbed off; he was hardening up under experience, developing a will of his own--and a secretive one, it seemed to me; and with Ronald Mirlees, at least, he was drifting out of touch. It seemed incredible this could happen with two men living together as we were in the midst of a strange race, but it was a palpable fact nevertheless, and it hurt me a little, though naturally my own pride kept me from saying anything to Poyning on the subject. When, however, about the eighth night in succession he took himself off alone after dark, and I saw one of our attendants slip out behind him, I judged the affair had gone far enough. If there was any spying to be done, I would take a hand in it myself.