“Here,” said Mr. McFarland, “we keep our most valuable tools and the diamonds used in giving to shaftings their finishing touches. Here also rest the six bars of steel of the mysterious, unknown formula. We hope soon to rediscover that formula, or that its inventor, through the agencies of the doctor of the sanitarium, will be restored to his normal mind and memory. An old and trusted employe presides over the vault during the day. It will be your task to guard it nights. At any time you feel yourself in danger, there are the secret doors, walls and passages I have shown you. They may be of great service to you in securing aid, if it is needed. And now I must bid you good night.”
“Good night.” Johnny’s own voice, as if coming from a cavern, sounded hollow to him.
As his employer disappeared from sight, however, he shook himself and attempted to remember something he had postponed, something of which his subconscious memory was striving to tell him.
Suddenly he started.
“The box! That lunch-box caught by the electro-magnet!”
The next instant he was hastening away to the cubby-hole where the box still rested.
As he put his hand to the door, a sinking feeling seized him. What if it were gone? The next instant found him reassured; with the handle of the box in his own right hand, he was hurrying back to his post of duty.
But what was that? Had his well-trained ear caught the sound of a footstep? With heart beating double-time, he stood in the shadow of a great punch-press and listened. Yes, there it was; a stealthy, gliding footstep.
Stooping, with a silent, tiger-like motion he crept forward until the steel door of the vault was within his view. There, in the shelter of a milling machine, he paused and crouched motionless as a cat.
He did not have long to wait, for out of the shadows there crept the dark, crouching form of a man.