Gradually I began to recover my wits and ponder over this mysterious affair, and a theory commenced to take shape. Clearly she was insane, or at least half-witted, and was quite incapable of drawing reasonable conclusions. And the more I thought it over, the more did several circumstances seem to confirm this view. My fire, for instance, with its smoke coming out of the chimney, and the supply of peat and firewood which Tiel or I were constantly bringing up. Had she noticed nothing of that? Also Tiel's frequent ascents of this back staircase to a part of the house supposed to be closed. She must be half-witted. And then I began to recall her brisk eye and capable air, and the idiot theory resolved into space. Only one alternative seemed left. She must be spying upon us, and aware of my presence all the time! But if so, what could I do? I felt even more helpless than I did that first night when my motor-cycle broke down. I could only sit and wait, revolver in hand. When I heard Tiel's step at last on the stairs, I confess that my nerves were not at their best. "We are betrayed!" I exclaimed. He stared at me very hard. "What do you mean?" he asked quietly, and I am bound to say this of Tiel, that there is something very reassuring in his calm voice. I told him hurriedly. He looked at me for a moment, began to smile, and then checked himself. "I owe you an apology, Belke," he said. "I ought to have explained that that woman is in my pay." "In your pay?" I cried. "And she has been so all the time?" He nodded. "And yet you never told me, but let me hide up in this room like a rat in a hole?" "The truth is," he replied, "that till I had got to know you pretty well, I was afraid you might be rash--or at least careless, if you knew that woman was one of us." "So you treated me like an infant, Mr Tiel?" "The life I have lived," said Tiel quietly, "has not been conducive to creating a feeling of confidence in my fellowmen's discretion--until I _know_ them. I know you now, and I feel sorry I took this precaution. Please accept my apologies." "I accept your apology," I said stiffly; "but in future, Mr Tiel, things will be pleasanter if you trust me." He bowed slightly and said simply-- "I shall." And then in a different voice he said-- "We have a visitor coming this afternoon to stay with us." "To stay here!" I exclaimed. "Another of _us_," he explained. "Another--in these islands? Who is he?" As I spoke we heard a bell ring. "Ah, here she is," said Tiel, going to the door. "Come down and be introduced whenever you like." For a moment I stood stock still, lost in doubt and wonder. "She!" I repeated to myself. VI. THE VISITOR.