Alas for Jack's expectations! The vault inside was as bare as Mother Hubbard's cupboard. There was not so much as a scrap of paper to be seen, let alone the dazzling stores he had pictured. The wall down each side were lined with shelves on which lay a thick, undisturbed coating of dust. Apparently there never had been anything kept there; at least not for a long time.
Jack was thoroughly disgusted. All that chasing around town for nothing! Was his benefactor's only purpose in taking those elaborate precautions to make a fool of his heir? Perhaps the old man had been really insane.
But having taken all that trouble Jack did not mean to give up until he had made very sure there was nothing to be gained from it. He examined the vault anew, and presently made a curious discovery in the steel door. Differing from any safe he had ever seen, the handle which operated the bolt ran right through to the inside of the door, also the dial and knob of the combination were reproduced inside.
"What did he want that for?" thought Jack, with perplexed brow. "Almost looks as if he wanted to lock himself up inside."
It was dark within the vault, and Jack lit the oil lamp and carried it in. He had not paid much attention to the back of the vault, for his eye had told him it was flush with the outer wall of the building, but he was now struck by the fact that whereas the sides of the vault were of concrete the back wall was of steel, and there were no shelves covering it.
In short, the lamp revealed the outline of a door in the back wall, a steel door so beautifully fitted that only the tiniest of lines marked its boundaries. In it was a tiny slit that Jack's fourth and last key exactly fitted. When it was pressed home, the door swung towards him on a spring.
Here he received another surprise. Instead of the shallow wall cupboard he expected, for he knew he was against the outer wall of the hotel, the beams of the lamp illuminated a large cupboard heaped with rubbish in the corners. At the same moment he was greatly startled to hear an electric bell start ringing somewhere further within.
He realized of course that he had stumbled on a secret way into the house adjoining the hotel. He remembered the aspect of that house from the street, shuttered, neglected, dirty. What would the inside reveal? The feeble, fretful alarm of the electric bell perturbed him. He closed the steel door and it stopped: he let it swing open and the sound recommenced. For whom was it a warning? Inside the closet on his right there was an ordinary wooden door. It did not help to compose his nerves to hear a soft urgent whining and scratching on the other side of it. The lamp trembled a little in his hand.
However there was nothing for it but to advance. Jack was boy enough to refuse to take a dare. He had been instructed to enter alone, and he was not sufficiently frightened to disobey. There was a kind of fascination in entering upon this voyage of discovery alone. Moreover he had no reason to suppose that a trap had been prepared for him.
Before venturing in, he took a careful survey of the closet. The litter in the corners consisted of old clothes, old boots, newspapers. A musty smell arose from it. His attention was caught by a broad black belt painted on the floor at his feet. Stooping, he touched it, and the black came off on his finger.