"Alas! my dear Frederick, the integrity of your heart will prevent your dissimulating a long time. Yes, although you have told your mother this morning she need have no fear, you are suffering this very hour, and perhaps more than in the past." Frederick's features contracted. David's penetration crushed him, and, to avoid his glances, he looked downward. David watched him closely, and continued: "Even your silence, my dear child, proves to me that the task which I have undertaken, to render you as happy as you have been in the past, is still to be fulfilled. No doubt you are astonished that I have not tried to undertake it before. The reason for it is simple enough. I did not wish to venture without absolute certainty, and it was only yesterday that I arrived at a certainty of conviction concerning the malady which oppresses you, indeed, which is killing you. Now I know the cause." Frederick trembled with dismay. This dismay, mingled with surprise, was painted in every look he cast upon David. Then, regretting the betrayal of his feelings, the young man relapsed into gloomy silence. "What I have told you, my child, astonishes you, and it ought to do so," replied David, "but," added he, in a tone of tender reproach, "why are you frightened at my penetration? When our friend, Doctor Dufour, healed you of a mortal ailment, was he not obliged, in order to combat your disease, to know the cause of it?" Frederick said nothing. During several minutes, as the two were approaching the hill upon which stood the lonely fir-trees, the son of Madame Bastien had from time to time glanced slyly and uneasily at his companion. He seemed to fear the miscarriage of some project which he had been contemplating since he had left his mother's house. Just as they finished talking, David observed that the road bordering on the crest of the hill changed into a narrow path which skirted the clump of fir-trees, and that Frederick, in an attitude of apparent deference, had stopped a moment, as if he did not wish to step in advance of his preceptor. David, attaching no importance to so natural and trivial an incident, passed on before the youth. At the end of a few moments, not hearing Frederick's step behind him, he turned around. The son of Madame Bastien had disappeared. CHAPTER XXV. David, bewildered with astonishment, continued to look around him. At his right extended the fallow ground, across which meandered the road which, with Frederick, he had just followed to arrive at the crest of the hill, and he discovered then for the first time, as he took several steps to the left, that on this side this bend of the ground was cut almost perpendicular, in a length of three or four hundred feet, and hung over a great wood, the highest summits of which reached only to a third of the escarpment.