Thor growled an answer, but I could not hear, the whistling wind and din, thunderous roaring from far below were growing louder. We were falling at an appalling speed, straight down the pit. It was a ride wild beyond imagination, with the air shrieking like fiends, and the fierce green rays streaming up around us. Through every fiber of my body, even though I wore the protective lead suit, tingled stronger vibrations of the stimulating force I had felt since entering this land. It was wildly exhilarating and intoxicating.
Thor's big, lead-clothed figure crouched, his gloved hand on the control lever. His cowled head was bent as he peered tautly down through a square quartz plate in the bottom of the disk. A giddy sensation akin to nausea shook me, so swift now was our fall.
"We approach Muspelheim!" came Thor's bellow over I the roar and shriek. "Hold tightly, Jarl Keith!"
His hand moved the lever in its slot. The tiny doors in the bottom of the disk closed a little. Our fall began to slow. Pressed hard against the disk, crushed by the deceleration, I peered down through the quartz view-plate with Thor. The end of the vertical pit was close below. I saw, beneath it, a vast, fiery space.
The disk slowed further, as Thor moved the lever. Finally it hung motionless again, its weight just balanced by the pressure of radiation from below. It had halted just where the vertical pit debouched into the roof of an inconceivably vast, blazing space. An underworld of terrible atomic radiance stretched away for miles from the rock wall beside which the pit entered.
"You look upon deep Muspelheim." Thor's voice reached me muffledly. "Once the home of the Aesir, it is the home now of the atomic fires and the creatures of the fires."
The scene before me was indescribably awe-inspiring. The vast dimensions of this mighty space beneath Earth's crust were enough to stagger the mind. This was no mere cavern, but an enormous hollow such as many have believed was left under the planet's surface by the hurling forth of the Moon.
The rocky roof was a mile above the floor. Our disk had halted just where the vertical pit entered the roof, close beside one rock wall of the great space. From the spot where Thor and I gazed, the subterranean world stretched off out of sight, to right and left and ahead.
Many miles away from us there shone a dazzling thing that dominated the whole vast, blazing fane with its brilliance. It was a colossal fountain of cold, white fire that gushed from a chasm in the floor. Hundreds of feet into the air it rose, falling back on itself in continual blinding spray. From it shot beams and banners of blinding light and force, a shaking, shuddering radiance.
All across the underworld rose similar but smaller geysers of white fire, gushing jets of radiance like that mighty distant one. Wherever the eye turned, it encountered such fiery fountains. They filled the underworld with a roaring that was deafening, and a terrific green-white radiance.