"They are very heavy," I answered.
"But how was the gold got away?" said Zena.
"I can only surmise as to that," I said with a smile. "The street which runs beside the bank is somewhat dimly lighted, and almost opposite to the private door of the bank there is an archway leading to a small yard and the premises of Thorne & Co., wine merchants. The archway is closed by a gate. The locked gate would present small difficulty to a gang which had carefully prepared their scheme, and very likely a motor car was driven under this archway ready to take the spoil away."
"It is possible, but I should want to find out something more about Frederick Ewing," said Zena.
"I am inclined to think that is a suggestion worth consideration," said Quarles. "This is a case in which one looks for negatives to a series of propositions. We may ask first, whether a gang, however expert, could have carried out such a robbery, knowing when and where to go and what to take, without some help from within. The answer seems to be, no. Was that information obtained merely through somebody's indiscretion? Hardly! Only a few people would be capable of giving the necessary information. Coulsdon, the porter, might give it. Did he? The fact that he was knocked insensible does not exonerate him; that might be part of a prearranged plan. On the whole, however, Ewing appears to be a more likely person. He was dishonest, that we know; he was in a position to give the information; he would be smarting under the disgrace of his dismissal; an offer of a substantial payment would, therefore, be tempting; and, moreover, he is not to be found."
"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.