“Sorry, Bob.”
“Forget that, too. Call me Mr. Galvin. You’ll have to do it regular beginning to-morrow. The girl will be back then.”
“All right,” agreed Briggs. “Don’t worry. I’ll be careful. But what about this job? That first post moved all right. How about hitting this one a few more cracks?”
He leaned to the floor and started to pick up a sledge hammer that had a piece of cloth wrapped about the head. Bob stopped him with a gesture.
“Give it another push,” he suggested.
The two men joined the one who was working at the post. Under their renewed efforts, the steel pillar began to budge. It slid slowly along the wall, with a rasping noise.
Betty could see Bob push the others down the passage as he began to examine the wall at the spot which had been covered by the sliding post. An excited exclamation came from his lips.
“Heave here,” he said in a low voice.
The three men united their efforts. They massed themselves against the wall.
To Betty’s amazement, the section of the wall opened at their force. Then Bob’s arms went out as he held the others back.