So Bertie the Badger returned once more to his native element and proceeded to exercise his discretion.  This took the form of continuing his aggressive tunnel in the direction of the Boche defensive gallery.  Next morning, encouraged by the absolute silence of the enemy’s miners, he made a farther and final push, which actually landed him in the “Piccadilly Tube” itself.

“This is a rum go, Howie!” he observed in a low voice to his corporal.  “A long, beautiful gallery, five by four, lined with wood, electrically lighted, with every modern convenience—­and not a Boche in it!”

“Varra bad discipline, sir!” replied Corporal Howie severely.

“Are you sure it isn’t a trap?”

“It may be, sirr; but I doot the oversman is awa’ to his dinner, and the men are back in the shaft, doing naething.”  Corporal Howie had been an “oversman” himself, and knew something of subterranean labour problems.

“Well, if you are right, the Boche must be getting demoralised.  It is not like him to present us with openings like this.  However, the first thing to do is to distribute a few souvenirs along the gallery.  Pass the word back for the stuff.  Meanwhile I shall endeavour to test your theory about the oversman’s dinner-hour.  I am going to creep along and have a look at the Boche entrance to the Tube.  It’s down there, at the south end, I think.  I can see a break in the wood lining.  If you hear any shooting, you will know that the dinner-hour is over!”

At the end of half an hour the Piccadilly Tube was lined with sufficient explosive material—­securely rammed and tamped—­to ensure the permanent closing of the line.  Still no Boche had been seen or heard.

“Now, Howie,” said Bertie the Badger, fingering the fuse, “what about it?”

“About what, sirr?” inquired Howie, who was not quite au fait with current catch-phrases.

“Are we going to touch off all this stuff now, and clear out, or are we going to wait and see?”

“I would like fine—­” began the Corporal wistfully.

“So would I,” said Bertie.  “Tell the men to get back and out; and you and I will hold on until the guests return from the banquet.”

“Varra good, sirr.”

For another half-hour the pair waited—­Bertie the Badger like a dog in its kennel, with his head protruding into the hostile gallery, while his faithful henchman crouched close behind him.  Deathly stillness reigned, relieved only by an occasional thud, as a shell or trench-mortar bomb exploded upon the ground above their heads.

“I’m going to have another look round the corner,” said Bertie at last.  “Hold on to the fuse.”

He handed the end of the fuse to his subordinate, and having wormed his way out of the tunnel, proceeded cautiously on all-fours along the gallery.  On his way he passed the electric light.  He twisted off the bulb and crawled on in the dark.

Feeling his way by the east wall of the gallery, he came presently to the break in the woodwork.  Very slowly, lying flat on his stomach now, he wriggled forward until his head came opposite the opening.  A low passage ran away to his left, obviously leading back to the Boche trenches.  Three yards from the entrance the passage bent sharply to the right, thus interrupting the line of sight.