"Then who was crying for help?" persisted the young captain.
"See here, cap'n, you are on the wrong trail," came from the older of the regulars. "Me and Bill's jest been having a little rumpus between ourselves. We meant no harm by it."
"I don't believe you," came from Major Morris, promptly. "There is some mystery here, and as sure as you're born I'm going to find out what it is!" he went on.
The major had scarcely finished when Ben's eyes fell to the floor, and he saw the outline of a trapdoor under one of the regular's feet. One edge of the door was raised about half an inch above the floor proper, as if the door had been opened and not put back evenly into place.
"Major, look at that trap-door!" he cried. "I'll wager they used it while we were coming up the outside stairs."
"You must be right, captain. If you'll—"
"We didn't use no trap-door," shouted the younger of the regulars, but he appeared much disconcerted over the discovery Ben had made.
"Captain, I have them covered," came from Major Morris, as he brought out the two pistols with which
