"The manager told him it would be impossible. Even if he had been willing to do it, against all regulations, it would still be impossible. For the strong-room and every cash receptacle in it was locked with two separate locks with different keys, and though he had one of these keys himself, it was useless without the other, which was in the possession of his second in command, who lived some distance out of London. This course is the usual precaution adopted in branch banks of this sort; opening and closing, morning and evening, have to be done by chief and assistant together. And I tell you, Brett, I believe that it was only the being informed of this fact that prevented Mayes from trying some of his hypnotic tricks on the bank manager; in which case there would have been a big bank robbery--perhaps something worse in addition." "Murder?" "Murder with a tourniquet, perhaps--perhaps with some other weapon; but, at any rate, probably with the Red Triangle. You know, of course--indeed I told you, I think--that in most cases--not all--it is necessary to get the subject's consent to the _first_ exercise of hypnotism on him. I told you also it is possible for the practised hypnotist, while the subject is under the influence of the _first_ experiment, to suggest to him a certain word or formula, or even a silent sign, which shall bring him under the influence at any other time, whenever the hypnotist chooses to repeat it--just as must have been done with Mr. Telfer, in the case of the Admiralty code. The first suggestion would not be the difficult thing it might seem--it would only require a little time and persuasion. Nothing would be said about hypnotism, of course; perhaps something about a little physical experiment, or the like, and then in a moment or two the subject would be in this creature's power for ever. Remember the little 'ceremony of initiation' that the scoundrel attempted to persuade you to submit to! That meant hypnotism--perhaps death.