The others were at his side in an instant. The sight was a staggering shock to all.

There, on the bottom of a black cavern that apparently extended under the whole flooring of the cow-shed, lay two bodies. Both were in French uniforms. Obviously one man was dead. The other moved slightly and gave another low moan that showed he was alive, although not conscious. Three huge rats scampered away in fright as the light was thrown upon them.

“Ollie,” said Tom, again taking the leadership, “you get a surgeon as quickly as you can. We’ve got to get that fellow out, and save his life if possible.”

Without a word Ollie was gone on the errand directed, while Tom, holding to the hands of George Harper and Buck Granger, lowered himself into the subterranean prison, the floor of which was not more than five feet below that of the shed.

Tom turned the living man over so as to see his face. It was drawn in lines of suffering and fixed in an expression of absolute terror. The whole body was emaciated almost beyond belief.

“Poor fellow,” murmured Tom, as he placed one arm under the shoulders of the soggy and mildewed uniform. “Left here to go stark mad and starve to death. Probably heard death rattle of his companion here as the rats were gnawing at him. Ugh!”

The man weighed no more than an average boy of fifteen or sixteen years. Tom raised the body carefully, lifted it to the height of the shed floor, and into the hands of the two youths waiting there. Tom himself was just climbing out of the pit when Ollie and a surgeon entered.

“What have we got here?” the latter asked, as with businesslike precision he strode to the still form on the floor, the boys making way for him.

In a few brief words Tom explained—told how Buck Granger first had been awakened, then how all of them had heard the moans, and of the discovery of the secret switch, and then of the cavern and the bodies within.

As Tom spoke the surgeon cast a queer look at him, but an instant later he was working over the unconscious Frenchman, a hand on his pulse, his ear to his heart.