But La Planta made no reply. Instead, he shrugged his shoulders, then tossed his cigarette into the water with a gesture of contempt. CHAPTER XVII. “NOBODY MUST KNOW!” Preston’s servant, an ex-soldier who had served under him in France, returned to the houseboat, but neither Preston nor Yootha had arrived. The man looked about him, puzzled. Then, concluding that his master must have been detained by friends on his way back, he began to attend to his work. But when an hour had passed, and still Preston did not return, he went outside and scanned the river with his master’s field-glasses. It was past seven, and he had dinner nearly ready. It would be annoying if his master stayed away for dinner without giving him warning. Presently a boat stopped alongside, and its sole occupant got out and came aboard. “Captain Preston about?” he inquired breezily. “I am dining with him.” “Dining with him, sir?” “Yes. Hasn’t he told you?” “He has not been here since four o’clock, sir. He and Miss Hagerston went out to tea and have not been back since. I have an important letter for him and wish he would return.” It was now Johnson’s turn to look puzzled. “I met him and Miss Hagerston at tea,” he said at last, “and they invited me to come and dine. I can’t understand it. Anyhow, I had better wait.” “If you would, sir. As he has invited you to dine he is bound to be back soon.” Johnson looked again at the man. “Haven’t I seen you somewhere before?” “Yes, sir, at Fig Tree Court.” “Of course. I remember.” He lay back in the deck-chair which he had taken, lit a cigarette, and began carelessly to focus the boats on the river through Preston’s binocular. At eight o’clock the man came back. “Hadn’t I better serve your dinner, sir?” he inquired tentatively. “I am sure the captain would not like you to be kept waiting. Something important must have detained him, sir, for he is always punctual to the moment, and of course there being no telephone----” “Thank you, but I will wait a little longer. If he is not back by half-past eight perhaps I will have something to eat, as I can’t get anything anywhere else now.” “Thank you, sir,” and the man retired with noiseless tread. But at half-past eight neither Preston nor Yootha had returned, nor had they by half-past nine. Johnson had waited until nine, then had eaten a light meal and gone away. The ex-soldier was becoming anxious. He pulled out of his pocket the long envelope addressed to his master, which had been brought by a man in flannels who had appeared to him a gentleman and had assured him the letter was most urgent and must be delivered at the earliest possible moment. “I wonder if this would throw some light on it?” he said aloud, as he eyed the envelope suspiciously. “So help me, I’d like to know.”