They adjourned to the smoke-room after dinner, and whilst Elk puffed luxuriously at one of his host’s best cigars, Dick wrote a brief note to the girl, who had been in his thoughts all that day. It was an unnecessary note, as such epistles are liable to be; but it might have had, as its excuse, the news that he had heard from Elk, only, for some reason, he never thought of that until after the letter was finished and sealed. When he turned to his companion, Elk propounded a theory. “I sent a man up to look at some chemical works. It’s a fake company—less than a dozen hands employed, and those only occasionally. But it has a very powerful electrical installation. It is an old poison gas factory. The present company bought it for a song, and two fellows we are holding were the nominal purchasers.” “Where is it?” asked Dick. “Between Newbury and Didcot. I found out a great deal about them for a curious reason. It appears there was some arrangement between the factory, when it was under Government control, that it should make an annual contribution to the Newbury Fire Brigade, and, in taking over the property, the company also took over that contract, which they’re now trying to get out of, for the charge is a stiff one. They told the Newbury Brigade, in so many words, to disconnect the factory from their alarm service, but the Newbury Brigade, being on a good thing and having lost money by the arrangement during the war, refused to cancel the contract, which has still three years to run.” Dick was not interested in the slightest degree in the quarrel between the chemical factory and the fire brigade. Later, he had cause to be thankful that conversation had drifted into such a prosaic channel; but this he could not foresee. “Yes, very remarkable,” he said absent-mindedly. * * * * * * A fortnight after the disappearance from town of Ray Bennett, Elk accepted the invitation of the American to lunch. It was an invitation often given, and only accepted now because there had arisen in Elk’s mind a certain doubt about Joshua Broad—a doubt which he wished to mould into assurance. Broad was waiting for the detective when he arrived, and Elk, to whom time had no particular significance, arrived ten minutes late. “Ten minutes after one,” said Elk. “I can’t keep on time anyhow. There’s been a lot of trouble at the office over the new safe they’ve got me. Somethin’s wrong with it, and even the lock-maker doesn’t know what it is.” “Can’t you open it?” “That’s just it, I can’t, and I’ve got to get some papers out to-day that are mighty important,” said Elk. “I was wondering, as I came along, whether, having such a wide experience of the criminal classes, you’ve ever heard any way by which it could be opened—it needs a proper engineer, and, if I remember rightly, you told me you were an engineer once, Mr. Broad?”