hereditary enemies--nor ever before had I known of two meeting other than in battle.

Evidently the reverses that had recently overtaken both peoples had resulted in an alliance between these two individuals--at least against the common enemy--and now I saw why Thurid had come so often out into the Valley Dor by night, and that the nature of his conspiring might be such as to strike very close to me or to my friends.

I wished that I might have found a point closer to the two men from which to have heard their conversation; but it was out of the question now to attempt to cross the river, and so I lay quietly watching them, who would have given so much to have known how close I lay to them, and how easily they might have overcome and killed me with their superior force.

Several times Thurid pointed across the river in my direction, but that his gestures had any reference to me I did not for a moment believe. Presently he and Matai Shang entered the latter's boat, which turned out into the river and, swinging round, forged steadily across in my direction.

As they advanced I moved my boat farther and farther in beneath the overhanging wall, but at last it became evident that their craft was holding the same course. The five paddlers sent the larger boat ahead at a speed that taxed my energies to equal.

Every instant I expected to feel my prow crash against solid rock. The light from the river was no longer visible, but ahead I saw the faint tinge of a distant radiance, and still the water before me was open.

At last the truth dawned upon me--I was following a subterranean river which emptied into the Iss at the very point where I had hidden.

The rowers were now quite close to me. The noise of their own paddles drowned the sound of mine, but in another instant the growing light ahead would reveal me to them.

There was no time to be lost. Whatever action I was to take must be taken at once. Swinging the prow of my boat toward the right, I sought the river's rocky side, and there I lay while Matai Shang and Thurid approached up the center of the stream, which was much narrower than the Iss.

As they came nearer I heard the voices of Thurid and the Father of Therns raised in argument.

"I tell you, Thern," the black dator was saying, "that I wish only vengeance upon John Carter, Prince of Helium. I am leading you into no trap. What could I gain by betraying you to those who have ruined my nation and my house?"

"Let us stop here a moment that I may hear your plans," replied the hekkador, "and then we may proceed with a better understanding of our duties and obligations."

To the rowers he issued the command that brought their boat in toward the bank not a dozen paces beyond the spot where I lay.

Had they pulled in below me they must surely have seen me against the faint glow of light ahead, but from where they finally came to rest I was as secure from detection as though miles separated us.

The few words I had already overheard whetted my curiosity, and I was anxious to learn what manner of vengeance Thurid was planning against me. Nor had I long to wait. I listened intently.

"There are no obligations, Father of Therns," continued the First Born. "Thurid, Dator of Issus, has no price. When the thing has been accomplished I shall be glad if you will see to it that I am well received, as is befitting my ancient lineage and noble rank, at some court that is yet loyal to thy ancient faith, for I cannot return to the Valley Dor or elsewhere within the power of the Prince of Helium; but even that I do not demand--it shall be as your own desire in the matter directs."

"It shall be as you wish, Dator," replied Matai Shang; "nor is that all--power and riches shall be yours if you restore my daughter, Phaidor, to me, and place within my power Dejah Thoris, Princess of Helium.

"Ah," he continued with a malicious snarl, "but the Earth man shall