a square of the rock wall of the cavern abruptly flew open beside them, as though hinged like a door. Inside it was the mouth of a soft-lit, man-high tunnel, and in its opening stood two men. They wore over their clothing shroud-like, loose-hanging robes of gray, asbestos-like material. They wore hoods of the same gray stuff over their heads, pierced with slits at the eyes and mouth. And each wore on his breast the blazing star-badge.
Through the eye-slits the eyes of the two surveyed Campbell and Ennis as they halted, transfixed by the sudden apparition. Then one of the hooded men spoke measuredly in a hissing, Mongolian voice.
"Are you who come here of the Brotherhood of the Door?" he asked, apparently repeating a customary challenge.
Campbell answered, his flat voice tremorless. "We are of the Brotherhood."
"Why do you not wear the badge of the Brotherhood, then?"
For answer, the inspector reached in his pocket for the strange emblem and fastened it to his lapel. Ennis did the same.
"Enter, brothers," said the hissing, hooded shape, standing aside to let them pass.
As they stepped into the tunnel, the hooded guard added in slightly more natural tones, "Brothers, you two are late. You must hurry to get your protective robes, for the ceremony soon begins."
Campbell inclined his head without speaking, and he and Ennis started along the tunnel. Its light, as sourceless as that of the great water-cavern, revealed that it was chiseled from solid rock and that it wound downward.
When they were out of sight of the two hooded guards, Ennis clutched the detective's arm convulsively.
"Campbell, he said the ceremony begins soon! We've got to find Ruth first!"
"We'll try," the inspector answered swiftly. "Those hooded robes are apparently issued to all the members to be worn during the ceremony as protection, for some reason, and once we get robes and get them on, Chandra Dass won't be able to spot us.
"Look out!" he added an instant later. "Here's the place where the robes are issued!"
The tunnel had debouched suddenly into a wider space in which were a group of men. Several were wearing the concealing hoods and robes, and one of these hooded figures was handing out, from a large rack of the robes, three of the garments to three dark Easterners who had apparently entered in the boat just ahead of the cutter.
The three dark Orientals, their faces gleaming with strange fanaticism, quickly donned the robes and hoods and passed hurriedly on down the tunnel. At once Campbell and Ennis stepped calmly up to the hooded custodians of the robes, and extended their hands.
One of the hooded figures took down two robes and handed them to them. But suddenly one of the other hooded men spoke sharply.
Instantly all the hooded men but the one who had spoken, with loud cries, threw themselves forward on Campbell and Paul Ennis.
Taken utterly by surprize, the two had no chance to draw their guns. They were smothered by gray-robed men, held helpless before they could move, a half-dozen pistols jammed into their bodies.
Stupefied by the sudden dashing of their hopes, the detective and the young American saw the hooded man who had spoken slowly lift the concealing gray cowl from his face. It was the dark, coldly contemptuous face of Chandra Dass.
