Billy, evidently forgetting his original determination not to cross the line of discretion, started to explore this cul-de-sac, this passage open only at one end.
His chum accepted the inevitable and doubled up with the leader.
“It’s an even bet that we will be yanked up for attempted burglary,” he gloomily predicted.
“Here’s about the point, I think,” mused Billy, “where we lay behind that revolving door; that is, providing we were now inside.”
“Well, what of it?” impatiently demanded Henri. “We certainly don’t intend to break in to prove your deduction.”
Billy had no response for this. He was curiously examining a postern, or door, in the wall cutting off the vaulted passage.
“Wonder if there is a combination to this thing?” He put the question to the test, closely inspecting every panel in the door from top to bottom.
“Old thumbs up surely had a way of getting through from this side,” continued the Bangor boy, “and it was not by key, either—no sign of a keyhole anywhere.”
The mechanician in Henri was aroused. The door puzzle was something in his particular line. With no less interest now than that displayed by his comrade, the expert began tapping up and down the solid surface with the haft of his pocket-knife.
Directly he turned a bright eye and a complacent smile upon the interested Billy.