For the handcuffed prisoner, whom he supposed to be standing so close to him that it was only necessary to reach out and touch him, had during that one moment in which he had raised his head to the top of the wall above him, from which proceeded the bat-like sound, most mysteriously vanished.
There were his footprints on the snow-covered walk, nor was there other prints anywhere to be seen upon the smooth surface of the street, save those made by the boy and himself, and pointing up—not down the street.
And this was all.
His handcuffed prisoner, who could not by any possibility have advanced a dozen steps through the snow in the brief space of time during which the policeman's attention had been withdrawn, had strangely, marvelously disappeared.
[CHAPTER V.]
BATS IN THE WALL.
Left to himself within the banking-room, Detective Hook, with the closest scrutiny, began a systematic examination of the rifled vault and its surroundings.
There was no evidence that the bank had been entered other than by the rear doors from the Rector street side.
And these doors, strange to relate, were unprotected, save by ordinary spring locks.