But before he could let it go, the two other men, moved as if by a single impulse, had sprung forward with a bound, and in the self-same tone and in the self-same words cried out with one accord, in a wildly excited voice, "For God's sake, don't throw! You don't know how dangerous it is!" Le Neve let his hand drop flat, and allowed the stone to fall from it. As he did so the two others stood back a pace, as if guarding him, but kept their hands still ready to seize the engineer's arm if he made the slightest attempt at motion. Eustace felt they were watching him as one might watch a madman. For a moment they were silent. Trevennack was the first to speak. His voice had an earnest and solemn ring in it, like a reproving angel's. "How can you tell what precious life may be passing below?" he said, with stern emphasis, fixing Le Neve with his reproachful eye. "The stone might fall short. It might drop out of sight. You might kill whomsoever it struck, unseen. And then"--he drank in a deep breath, gasping--"you would know you were a murderer." Walter Tyrrel drew himself up at the words like one stung. "No, no! not a murderer!" he cried; "not quite as bad as a murderer! It wouldn't be murder, surely. It would be accidental homicide--unintentional, unwilled--a terrible result of most culpable carelessness, of course; but it wouldn't be quite murder; don't call it murder. I can't allow that. Not that name by any means.... Though to the end of your life, Eustace, if you were to kill a man so, you'd never cease to regret it and mourn over it daily; you'd never cease to repent your guilty carelessness in sackcloth and ashes." He spoke so seriously, so earnestly, with such depth of personal feeling, that Trevennack, starting back, stood and gazed at him slowly with those terrible eyes, like one who awakens by degrees from a painful dream to some awful reality. Tyrrel winced before his scrutiny. For a moment the elder man just looked at him and stared. Then he took one step forward. "Sir," he said, in a very low voice, half broken with emotion, "I had a dear son of my own once; a very dear, dear son. He was killed by such an ACCIDENT on this very spot. No wonder I remember it." Mrs. Trevennack and Cleer both gave a start of surprise. The man's words astonished them; for never before, during fifteen long years, had that unhappy father alluded in any way in overt words to his son's tragic end. He had brooded and mused over it in his crushed and wounded spirit; he had revisited the scene of his loss whenever opportunity permitted him; he had made of his sorrow a cherished and petted daily companion; but he had stored it up deep in his own inmost heart, never uttering a word of it even to his wife or daughter. The two women knew Michael Trevennack must be profoundly moved, indeed, so to tear open the half-healed wound in his tortured bosom before two casual strangers.