"Of course, it was Silwood," argued Gilbert; "it must have been he. The waster said the workman was flurried, went away hurriedly, but returned in half an hour. What does that mean, taken in connection with the fact that next morning Silwood left London? It must have been no light thing which made _him_ flurried. He intended going to Stepney, started, and then changed his mind. Not like _him_ either, to change his mind in that way. Something must have happened." Then the thought came leaping into his mind which explained everything. "It must have been because Morris Thornton was lying dead in Silwood's room--that accounts for his agitation and indecision." After that he asked himself the inevitable question-- "Had Silwood said or done anything to cause such a shock to Thornton as killed him? If so, what?" But this was a question he could not answer now. The key to the mystery lay with Silwood, and it was possible, even probable, he had made good his escape to America, if it was to America he was gone. America was a wide word, Gilbert mused, but the arm of Justice was long. Yet the search all over America--was that not like looking for a needle in a haystack? And the time which would almost certainly be occupied in the quest--what might not happen in the interim? With these questions, and such as these, Gilbert was distracted during his journey, and the news which met him on his arrival in London made his heart heavy as lead. His brother Ernest was at the station when his train steamed in. Gilbert observed he looked pale and sad. "How is father?" were Gilbert's first words. "Oh, it is terrible!" exclaimed Ernest. "Is he worse?" "Yes, he is worse. He will never be himself again, I fear. He is out of his mind." "Out of his mind!" cried Gilbert, but in his heart he was saying it was no wonder that his father had become insane, considering all he had borne during the past two months. "Isn't it dreadful?" "It may be only temporary," Gilbert suggested. "The doctors who have seen him do not give us much hope." "You have had specialists called in?" "Certainly." "What form does his trouble take?" "He is not at all violent; indeed, he is gentleness itself. But his memory seems a blank, and he does not speak except to say one sentence, and it breaks one's heart to hear him say it." "What does he say?" "He asks, 'What o'clock is it?' but he does not know what he says. If you tell him the time, he does not comprehend you. That was how mother found his trouble out. One night he had a sort of fit in bed; when it passed he asked, 'What o'clock is it?' and mother told him. He asked again, 'What o'clock is it?' and mother again told him. But he immediately inquired once more, 'What o'clock is it?' and then she began to surmise something was very wrong with him." "Poor mother!" exclaimed Gilbert. "How is she?"