Murilo realized that Conan supposed the mirror to be a window through which they were looking.
“He does not see us,” answered the priest. “We are looking into the chamber above us. That door that Thak is guarding is the one at the head of these stairs. It is simply an arrangement of mirrors. Do you see those mirrors on the walls? They transmit the reflection of the room into these tubes, down which other mirrors carry it to reflect it at last on an enlarged scale in this great mirror.”
Murilo realized that the priest must be centuries ahead of his generation, to perfect such an invention; but Conan put it down to witchcraft and troubled his head no more about it.
“I constructed these pits for a place of refuge as well as a dungeon,” the priest was saying. “There are times when I have taken refuge here and, through these mirrors, watched doom fall upon those who sought me with ill intent.”
“But why is Thak watching that door?” demanded Murilo.
“He must have heard the falling of the grating in the tunnel. It is connected with bells in the chambers above. He knows someone is in the pits, and he is waiting for him to come up the stairs. Oh, he has learned well the lessons I taught him. He has seen what happened to men who come through that door, when I tugged at the rope that hangs on yonder wall, and he waits to mimic me.”
“And while he waits, what are we to do?” demanded Murilo.
“There is naught we can do, except watch him. As long as he is in that chamber, we dare not ascend the stairs. He has the strength of a true gorilla and could easily tear us all to pieces. But he does not need to exert his muscles; if we open that door he has but to tug that rope, and blast us into eternity.”
“How?”
“I bargained to help you escape,” answered the priest; “not to betray my secrets.”
Murilo started to reply, then stiffened suddenly. A stealthy hand had parted the curtains of one of the doorways. Between them appeared a dark face whose glittering eyes fixed menacingly on the squat form in the scarlet robe.
“Petreus!” hissed Nabonidus. “Mitra, what a gathering of vultures this night is!”
The face remained framed between the parted curtains. Over the intruder’s shoulder other faces peered — dark, thin faces, alight with sinister eagerness.
“What do they here?” muttered Murilo, unconsciously lowering his voice, although he knew they could not hear him.
“Why, what would Petreus and his ardent young nationalists be doing in the house of the Red Priest?” laughed Nabonidus. “Look how eagerly they glare at the figure they think is their arch-enemy. They have fallen into your error; it should be amusing to watch their expressions when they are disillusioned.”
Murilo did not reply. The whole affair had a distinctly unreal atmosphere. He felt as if he were watching the play of puppets, or as a disembodied ghost himself, impersonally viewing the actions of the living, his presence unseen and unsuspected.
He saw Petreus put his finger warningly to his lips, and nod to his fellow conspirators. The young nobleman could not tell if Thak was aware of the intruders. The ape-man’s position had not changed, as he sat with his back toward the door through which the men were gliding.
“They had the same idea you had,” Nabonidus was muttering at his ear. “Only their reasons were patriotic rather than selfish. Easy to gain access to my house, now that the dog is dead. Oh, what a chance to rid myself of their menace once and for all! If I were sitting where Thak sits — a leap to the wall — a tug on that rope —”
Petreus had placed one foot lightly over the threshold of the chamber; his fellows were at his heels, their daggers glinting dully. Suddenly Thak rose and wheeled toward him. The unexpected horror of his appearance, where they had thought to behold the hated but familiar countenance of Nabonidus, wrought havoc with their nerves, as the same spectacle had wrought upon Murilo. With a shriek Petreus recoiled, carrying his companions backward with him. They stumbled and floundered over each other; and in that instant Thak, covering the distance in one prodigious, grotesque leap, caught and jerked powerfully at a thick velvet rope which hung near the doorway.
Instantly the curtains whipped back on either hand, leaving the door clear, and down across it something flashed with a peculiar silvery blur.
“He remembered!” Nabonidus was exulting. “The beast is half a man! He had seen the doom performed, and he remembered! Watch, now! Watch! Watch!”
