Kennedy had begun mildly enough, owing to the experience which his subordinate had so recently undergone, but, at this point, the autocrat in him got the better of his sympathy. “What the devil did you mean, though, by going into his cell, keys and all, like a confounded imbecile?” he demanded harshly. “Isn’t that the first thing you had drilled into that reënforced-concrete dome of yours--not to give any of these fellows a chance to jump you when you have your keys with you? If you hadn’t fallen for his little game----” “But I didn’t fall for nothing, warden!” the keeper interrupted warmly. “I didn’t go into his cell at all. I know better than that, believe me!” “You didn’t--what? What are you trying to put over, Bradley?” Kennedy burst out. “You were found in his cell, with the door unlocked and the keys gone, not to mention Number Sixty Thousand One Hundred and Thirteen, curse him! Maybe that ain’t proof.” “It ain’t proof,” insisted the keeper, “no matter how it looks. He called to me, and I started toward the grating to see what he wanted. He fixed his eyes on me, like he was looking me through and through, and made some funny motions with his hands. I’ll swear that’s all I remember. If I was found in his cell, I don’t know how I got there, or anything about it, so help me!” The warden started to give Bradley another tongue-lashing, but Nick interposed. “He’s telling the truth, Kennedy,” he said. “But how in thunder----” “Very easily. It hadn’t occurred to me before, but it is evident that Grantley hypnotized him through the bars and then commanded him to unlock the door and come inside. There is nothing in hypnotism to interfere; on the contrary, that would be the easiest and surest thing to do, under the circumstances. Grantley is too clever to try any of the old, outworn devices--such as feigning sickness, for instance--in order to get a keeper in his power. All that was necessary was for him to catch Bradley’s eye. The rest was as easy as rolling off a log. When he got our friend inside, he put him to sleep, took his keys and his outer clothing, and then--good-by, Sing Sing! It’s rather strange that he succeeded in getting away without discovery of the deception, but he evidently did; or else he bribed somebody. You might look into that possibility, if you think best. The supposition isn’t essential, however, for accident, or good luck, might easily have aided him. As for the means he used to cover his trail after leaving the vicinity of the prison, we need not waste any time over that question. Fortunately, we have hit upon his trail down the river, and all that remains to do is to keep on it, in the right direction, until we come up with him. It may be a matter of hours or days or months, but Grantley is going to be brought back here before we’re through. You can bank on that, gentlemen. And when I return him to you it will be up to you to take some extraordinary precautions to see that he doesn’t hypnotize any more keepers.”