She shyly bent her head and answered him, "To-morrow thou shalt know, my father." Then she hid her blushing face upon his shoulder. "I have a favour to ask of thee; but--I would fain not speak of it this evening." Then, as though fearing that he would wrest from her the secret of her joy, she stole swiftly to her room, and from her window looked across the lake, now shimmering in the silver moonbeams. For long she sat there motionless, dreaming youth's fond dreams; dwelling, in loving tenderness, on every word and look she could recall of Leonard while the boat had drifted here and there, and the lap, lap, lap, of the ripples against the sides had kept up a soft musical accompaniment to the rhythm of love's heart-beats. CHAPTER XXI. THE GREAT DEVIL-TREE. In pursuance of their design of making signals from the summit of Roraima, the two friends made further explorations of the northern side. And this led them into an adventure, one day, that had well-nigh proved fatal to them both. On mentioning their intention to Monella, he had at first objected; but, upon Leonard's reminding him of the anxiety and distress Templemore's mother and _fiancée_ might be, too probably were, in, he had given a reluctant consent. "Your friends, Dr. Lorien and his son, talked of coming back again," he remarked. "Do you think they are likely to make the journey with Matava, and to be coming to seek for you?" "Certainly they are coming into this neighbourhood, after orchids," Leonard replied; "and, now you speak of it--though I had not thought about it lately--the news Matava will probably take back may cause such anxiety that they may hurry to get here sooner than they would otherwise have been likely to, in order to make inquiry about us on the spot." "Matava might lead them to the cavern, if they came to Daranato," said Monella thoughtfully. "Yes; of course that is possible." "And a very little ingenuity or a small charge of powder would force an opening; and their way would then be easy to get up here?" "Certainly." Monella's face clouded. "That must not be; you must clearly understand that you must tell me in time if there seems any such probability. I wish not to seem unfriendly towards your friends--and personally I liked them--but to allow them to come in here would be as the beginning of a flood, as the letting out of water. It cannot, must not be." "Well, after all, it is only a supposition," observed Jack. "Time enough to deal with it, if the occasion actually arise. They were going on to Rio on some law business which was likely to occupy them some time; they might be detained there indefinitely, they said." "Quite so," Monella answered decisively. "Only, remember, I rely upon you to inform me in time. And be very cautious and vigilant upon that side of the country, for, as you know, it is in that direction that Coryon and his people have their habitation."