"Can't make out why the beggars scooted," muttered Bob Dashwood. "This place has been turned into a regular redoubt, and might have been held successfully against a division. There is something at the bottom of it, Dennis, and the mind of Brother Boche is a subtle and a crafty mind. Look!" And he pointed to a long line of underclothing hanging above the stoves. "They've even left their washing when they cleared out."

His speculations terminated abruptly as an electric bell rang somewhere in the darkness.

"Great Scott!" cried Dennis, stabbing the gloom with the beam of his pocket-torch. "There's another room here, and the place is evidently in communication with their headquarters."

He ran in the direction of the sound, and the door led him into the engine-room of the brewery, a mysterious place smelling of oil. Wheels, shafts and boilers met his eye, but he paid no heed to them, for the bell still rang; and Bob, limping painfully after him, heard the sharp cry he gave, and saw him bending down in a huge cavity on which he flashed his light.

"I say, Bob!" he called excitedly. "The chimney overhead is fitted with a wireless installation, and here's a complete outfit of field telegraph and telephone!"

"Smash it; it's worse than useless to us, for we don't know their code," was the practical advice of the captain.

"Hold on!" chuckled Dennis. "They don't talk by code. We may hear things yet!" And he unhooked the telephone receiver.

Bob's eyes opened very wide, and, leaning on his rifle-crutch, he explored his brother's pocket for a cigarette and lit it.

"Well, what's it all about?" he asked impatiently, his eyes riveted on the delighted smile that wreathed the listener's face.

Dennis made a hasty gesture with his hand and continued to listen.