He led the way back into the building whence they had emerged. But once inside they did not stop. The greenish radiance penetrated even there. They hurried over to a wide metal door that slid silently open when Spurlin pressed a hidden button. Revealed to their gaze was a dark narrow tunnel, leading downward.
"What about the Martian?" Ross said, addressing Spurlin.
"He goes along!" Jim snapped, and Kaarji looked at him gratefully.
"All right," Spurlin murmured softly. "No harm if he comes. But I don't think he'll last long, no Martian ever does in this city."
If Kaarji heard the words he did not show it, as he followed Jim into the tunnel.
"About your brother," Spurlin spoke brusquely out of the darkness as they moved along. "Yes, he arrived here all right. For a while, Frank Landor was with our secret little group down here below. But—there's something about that greenish atmosphere, something exhilerating but also deadly, in a very subtle and insidious way. Sometimes it increases, penetrates even down to us, through walls and things. But there are some men who—"
"Yes, I know," Jim's voice was as dead as the hope within him. "Frank was one of those men. He couldn't stay cooped up here. He was curious, he had to find out—things, and the reason for things. That what you're trying to tell me?"
"That's about it. Like others who have come here he had to go up into the city, searching, trying to solve its secret. Every day he and a few others went up. Always they returned to us here, exhausted, until one day—they just didn't come back."
In silence they continued along the winding passage. Jim was thinking of his brother now, with a dawning realization that he would probably never again see him alive. He was thinking of other things too. Of that menacing greenness in the city above. Of Spurlin who seemed so calloused and unconcerned. Of the legendary emerald of M'Tonak, the lure for countless men in ages past.