"But not with both at once?" "That would not be practical," said Sir Oswald shortly. "No," said Socks thoughtfully. "I suppose that would be a bit too subtle." "It would be a grand thing now in a Government department," observed Mr. O'Rourke, "if one could keep the right hand from knowing what the left hand was doing." "Can you use both hands?" "No, indeed. I'm the most right-handed person that ever was." "But you deal cards with your left hand," said the observant Bateman. "I noticed the other night." "Oh, but that's different entirely," said Mr. O'Rourke easily. A gong with a sombre note pealed out and everyone went upstairs to dress for dinner. After dinner Sir Oswald and Lady Coote, Mr. Bateman and Mr. O'Rourke played bridge and Jimmy passed a flirtatious evening with Socks. The last words Jimmy heard as he retreated up the staircase that night were Sir Oswald saying to his wife: "You'll never make a bridge player, Maria." And her reply: "I know, dear. So you always say. You owe Mr. O'Rourke another pound, Oswald. That's right." It was some two hours later that Jimmy crept noiselessly (or so he hoped) down the stairs. He made one brief visit to the dining-room and then found his way to Sir Oswald's study. There, after listening intently for a minute or two, he set to work. Most of the drawers of the desk were locked, but a curiously shaped bit of wire in Jimmy's hand soon saw to that. One by one the drawers yielded to his manipulations. Drawer by drawer he sorted through methodically, being careful to replace everything in the same order. Once or twice he stopped to listen, fancying he heard some distant sound. But he remained undisturbed. The last drawer was looked through. Jimmy now knew--or could have known had he been paying attention--many interesting details relating to steel; but he had found nothing of what he wanted--a reference to Herr Eberhard's invention or anything that could give him a clue to the identity of the mysterious No. 7. He had, perhaps, hardly hoped that he would. It was an off-chance and he had taken it--but he had not expected much result--except by sheer luck. He tested the drawers to make sure that he had relocked them securely. He knew Rupert Bateman's powers of minute observation and glanced round the room to make sure that he had left no incriminating trace of his presence. "That's that," he muttered to himself softly. "Nothing there. Well, perhaps I'll have better luck to-morrow morning--if the girls only play up." He came out of the study, closing the door behind him and locking it. For a moment he thought he heard a sound quite near him, but decided he had been mistaken. He felt his way noiselessly along the great hall. Just enough light came from the high vaulted windows to enable him to pick his way without stumbling into anything.