“What about food?” Jimmy asked. “And oxygen?”
“There’s a lot about that Copt tribe we don’t know. Food—well, fish and mushrooms are staples. The Midnight Sea lies under the Sahara. Ages ago the water in it made the desert itself a sea, but it drained underground at last. As for oxygen, there must have been outlets before we blasted some, though they’ve never been discovered. Possibly through river caves that drain into the sea.”
Captain Brady rubbed his eyes with the back of one mahogany hand. “A lot we don’t know about the Copts. Savage, ferocious—but marvelous miners. The Legion’s posted there to keep order. Prevent raids on the surface tribes. The Copts worship Isis, or the Moon—I dunno which. Probably they’re the same. Keep clear of them unless you’re armed; don’t monkey with their religion; and don’t enter any passages engraved with the emblems of the Moon and the sistrum.”
“Why not?”
“Religion, youngster. No white man has ever seen the Ka’aba—the Black Stone—at Mecca. It’s sacred to the Moslem, just as the Alu—the group of deepest caverns—are sacred to the Copts. They say Amon-Ra is down there.”
Jimmy’s eyebrows lifted. “Amon-Ra? The ancient Egyptian god?”
“Right. ‘The Hidden Light.’ We have a sort of armed truce with the Copts, provided we don’t interfere too much. When they get out of line, we whip them back. Figuratively, of course.” Brady’s hand touched the buttoned holster at his thigh.
“What did you say the sacred caves were called?” Phil asked suddenly.
“Alu.”
“What does it mean?”