"Follow?" I echoed stupidly.
"Follow!" he said. "She came to show us the way! Follow? I'd follow her through a thousand hells!"
And with Olaf at one end, O'Keefe at the other, both of them with automatics in hand, and Marakinoff and I between them, we stepped over the threshold.
At our right, a few feet away, the passage ended abruptly in a square of polished stone, from which came faint rose radiance. The roof of the place was less than two feet over O'Keefe's head.
A yard at left of us lifted a four-foot high, gently curved barricade, stretching from wall to wall—and beyond it was blackness; an utter and appalling blackness that seemed to gather itself from infinite depths. The rose-glow in which we stood was cut off by the blackness as though it had substance; it shimmered out to meet it, and was checked as though by a blow; indeed, so strong was the suggestion of sinister, straining force within the rayless opacity that I shrank back, and Marakinoff with me. Not so O'Keefe. Olaf beside him, he strode to the wall and peered over. He beckoned us.
"Flash your pocket-light down there," he said to me, pointing into the thick darkness below us. The little electric circle quivered down as though afraid, and came to rest upon a surface that resembled nothing so much as clear, black ice. I ran the light across—here and there. The floor of the corridor was of a substance so smooth, so polished, that no man could have walked upon it; it sloped downward at a slowly increasing angle.
"We'd have to have non-skid chains and brakes on our feet to tackle that," mused Larry. Abstractedly be ran his hands over the edge on which he was leaning. Suddenly they hesitated and then gripped tightly.
"That's a queer one!" he exclaimed. His right palm was resting upon a rounded protuberance, on the side of which were three small circular indentations.
"A queer one—" he repeated—and pressed his fingers upon the circles.
There was a sharp click; the slabs that had opened to let us through swung swiftly together; a curiously rapid vibration thrilled through us, a wind arose and passed over our heads—a wind that grew and grew until it became a whistling shriek, then a roar and then a mighty humming, to which every atom in our bodies pulsed in rhythm painful almost to disintegration!