"This part of the wall is quite loose," exclaimed Mayne.
"Steady," whispered Atherton, warningly. "Keep quiet, you fellows."
The Leader felt the face of the granite slab. It was certainly loose, but the joints of the masonry were not wide enough for his fingers to obtain a grip.
"Hold my lantern a minute, Phillips," he said. "I'll see what I can do with my knife. You have matches handy? Good! Now blow out all the lights."
These orders were promptly carried out. The darkness was darkness indeed. To the excited lads it seemed to have weight. Even Phillips, strong-minded as he was, grasped his box of matches tightly, as if he derived some consolation from the fact that he held a weapon that could be used to effectually banish the stifling sensation imparted by the intense darkness.
Scratching lightly with the blade of his knife, Atherton at length found the joint of the stonework once more. Deftly inserting the blade, he cautiously prised the block of granite. It gave, then slid back in its position.
"The stone is pivoted," he whispered. "Where's your hand, Mayne? Put it here, and when I swing the stone out half an inch try and get a grip."
The blade bent almost to breaking point. The stone swung outwards. Mayne, gripping the rough edge, sought to retain a tenacious hold.
"It's slipping," he gasped in low, tense tones. Atherton instantly drove the blade home till the handle was tightly wedged in the enlarged orifice. Then, relaxing his hold upon the knife, he aided Mayne with his wiry fingers.
The block swung stiffly outwards another inch, then with hardly any resistance it turned, disclosing an aperture sufficiently large for a man to crawl through.