"I think it very probable that information was obtained from Ewing," I said. "But it may have been given without any criminal intention. In my opinion the planning of the robbery must have begun before Ewing's dismissal. Besides, though I have failed to trace Ewing, I do not find anything against him beyond this matter of the petty cash. There are no debts worth mentioning, and no entanglements of any kind apparently." "So we get no definite answer regarding him," said the professor; "we must, so to speak, put him aside for further consideration. Let us get back to the gang for a moment. That money would require a lot of moving, Wigan. Assuming Coulsdon to be honest, the door of the strong-room was intact at two o'clock on Sunday morning. The tell-tale clock is a witness to this, and seven hours later the alarm was given. I do not say that a motor car might not have been loaded as you suggest and driven out of the city without attracting the notice of the police, but if you ask me whether it is likely I must decidedly answer in the negative." "The fact remains that the gold was got away," I answered. "You cannot alter that." "Our methods sometimes clash, Wigan. You make a theory to fit the facts; I get a theory first, and then look for facts to fit it. I grant yours is the more orthodox method; still, what is considered orthodox has sometimes been shown to be wrong; and as for facts--well, if I choose to think that this gold has not left the city, how can you convince me beyond all dispute that it has? You can't. You do not know. For instance, it might be concealed in this man Bowman's office. Say you are able to prove that it isn't, there are still many other offices in the building where it might be hidden, ready to be got rid of gradually. At this stage of the inquiry, at any rate, we are not prepared to guarantee the honesty of all the firms in the block of buildings adjoining the bank." "So that is your theory?" I said, somewhat impressed by it, I admit. "No, it isn't," said Quarles. "I was merely showing how unstable was your central fact. No, my theory is quite different." "May I hear what it is?" "I agree with Zena. Continue to hunt for Frederick Ewing. Get a dozen men on to the business, if you like. Instruct them to pick up the most trivial items of information concerning him. Run his companions to earth, find out all about his debts, however small they may be; that's the line along which you are likely to pick up the clew. If you can manage to put another detective on the job with you, I am a candidate for the post. I should like to see the strong-rooms and the window, and to ask a few questions." My suggestion that Christopher Quarles should be associated with me in the inquiry met with some opposition. The officials of the bank seemed a little nervous of too much publicity. The fact of the robbery, quite apart from the actual loss, had injured the bank considerably. However, all objections were overruled.