In the ornate chamber where he was to sleep, he glanced up at the slot-like skylights. Some were wide enough to admit the body of a slender man, supposing the glass were broken.

Ranged along the wall behind the dais were rows of glass-covered shelves. And on those shelves hundreds of human heads, perfectly preserved, stared at the startled watchers with emotionless eyes, as they had stared for only the gods knew how many months and years.

Murilo saw that it was a panel of heavy glass that had fallen across the doorway. Through it he saw the pallid faces of the conspirators. Petreus, throwing out his hands as if to ward off a charge from Thak, encountered the transparent barrier, and from his gestures, said something to his companions. Now that the curtains were drawn back, the men in the pits could see all that took place in the chamber that contained the nationalists. Completely unnerved, these ran across the chamber toward the door by which they had apparently entered, only to halt suddenly, as if stopped by an invisible wall.

"The jerk of the rope sealed that chamber," laughed Nabonidus. "It is simple; the glass panels work in grooves in the doorways. Jerking the rope trips the spring that holds them. They slide down and lock in place, and can only be worked from outside. The glass is unbreakable; a man with a mallet could not shatter it. Ah!"

I am bound for Kush, to trade beads and silks and sugar and brass-hilted swords to the black kings for ivory, copra, copper ore, slaves and pearls."

It was guided by the long sweep from the poop, and propulsion was furnished mainly by the broad striped silk sail, aided by a jibsail.

The sun beat down from day to day with fiercer heat, and the canopies were run up--striped silken cloths that matched the shimmering sail and the shining goldwork on the prow and along the gunwales.

Furs and satin cushions littered the floor.