At that farther end was a flat dais of black basalt upon which stood five hooded men, four wearing the blazing double-star on their breasts, the fifth, a triple-star. Two of them stood beside a cubical, weird-looking gray metal mechanism from which upreared a spherical web of countless fine wires, unthinkably intricate in their network, many of them pulsing with glowing force. The sourceless light of the cavern and the tunnel seemed to pulse from that weird mechanism.
Up from that machine, if machine it was, soared the black basalt wall of that end of the cavern. But there above the gray mechanism the rough wall had been carved with a great, smooth facet, a giant, gleaming black oval face as smooth as though planed and polished. Only, at the middle of the glistening black oval face, were carven deeply four large and wholly unfamiliar characters. As Ennis and Campbell stared frozenly across the awe-inspiring place, sound swelled from the hundreds of throats. A slow, rising chant, it climbed and climbed until the basalt roof above seemed to quiver to it, crashing out with stupendous effect, a weird litany in an unknown tongue. Then it began to fall.
Ennis clutched the inspector's gray-robed arm, "Where's Ruth?" he whispered frantically. "I don't see any prisoners."
"They must be somewhere here," Campbell said swiftly. "Listen"
As the chant died to silence, on the dais at the farther end of the cavern the hooded man who wore the triple-jeweled star stepped forward and spoke. His deep, heavy voice rolled out and echoed across the cavern, flung back and forth from wall to rocky wall.
"Brothers of the Door," he said, "we meet again here in the Cavern of the Door this year, as for ten thousand years past out forefathers have met here to worship They Beyond the Door, and bring them the sacrifices They love.
"A hundred centuries have gone by since first They Beyond the Door sent their wisdom through the barrier between their universe and ours, a barrier which even They could not open from their side, but which their wisdom taught our fathers how to open.
"Each year since then have we opened the Door which They taught us how to build. Each year we have brought them sacrifices. And in return They have given us of their wisdom and power. They have taught us things that lie hidden from other men, and They have given us powers that other men have not.
"Now again comes the time appointed for the opening of the Door. In their universe on the other side of it, They are waiting now to take the sacrifices which we have procured for them. The hour strikes, so let the sacrifices be brought."
As though at a signal, from a small opening at one side of the cavern a triple file of marchers entered. A file of hooded gray members of the Brotherhood flanked on either side a line of men and women who did not wear the hoods or robes. They were thirty or forty in number. These men and women were of almost all races and classes, but all of them walked stiffly, mechanically, staring ahead with unseeing, distended eyes, like living corpses.
"Drugged!" came Campbell's shaken voice. "They're all drugged, and don't know what is going on."
Ennis' eyes fastened on a small, slender girl with chestnut hair who walked at the end of the line, a girl in a straight tan dress, whose face was white, stiff, like those of the others.
"There's Ruth!" he exclaimed frantically, his cry muffled by his hood.
He plunged in that direction, bus Campbell held him back.
