There was the possibility that Whitey Mack and Lannigan were already above, waiting for him; but, even if they were not already there and he got away before they came, it was imperative that no one should know that Larry the Bat had come and gone.
He reached the landing, and paused again, his right hand, with a vicious muzzle of his automatic peeping now from between his fingers, thrown a little forward.

It was black, utterly black, around him.

Again that stealthy, catlike tread--and his ear was at the keyhole of the Sanctuary door.

A full minute, priceless though it was, passed; then, satisfied that the room was empty, he drew his head back from the keyhole, and those slim, tapering fingers, that in their tips seemed to embody all the human senses, felt over the lock.

Apparently it had been undisturbed; but that was no proof that Whitey Mack had not been there after finding the metal case.