My greatest obstacle to overcome now was the guard on the roof, where I had no doubt but that I should find several warriors. It might be difficult to convince them that even a noble would go flying alone at this time of night, but when I reached the roof there was not a single warrior in sight.

It took me but a moment to find the flier I had selected for the adventure when I had been there before, and but another moment to climb to its controls and start the smooth, silent motor.

The night was dark; neither moon was in the sky, and for that I was thankful. I rose in a steep spiral until I was high above the city; then I headed for the tower of Nastor's palace where Llana of Gathol was imprisoned.

The black hull of the flier rendered me invisible, I was sure, from the avenues below on a dark night such as this; and I came to the tower with every assurance that my whole plan had worked out with amazing success, even in spite of the untoward incidents that had seemed about to wreck it in its initial stages.

As I drew slowly closer to the windows of Llana's apartment, I heard a woman's muffled scream and a man's voice raised in anger. A moment later the prow of my ship touched the wall just below the window; and, seizing the bow line, I leaped across the sill into the chamber, Myr-lo's sword in my hand.

Across the room, a man was forcing Llana of Gathol back upon a couch. She was striking at him, and he was cursing her.

"Enough!" I cried, and the man dropped Llana and turned toward me. It was Nastor, the dator.

"Who are you?" he demanded. "What are you doing here?"

"I am John Carter, Prince of Helium," I replied; "and I am here to kill you."

He had already drawn, and our swords crossed even as I spoke.

"Perhaps you will recall me better as Dotar Sojat, the slave who cost you one hundred thousand tanpi," I said; "the prince who is going to cost you your life."

He commenced to shout for the guard, and I heard the sound of running footsteps which seemed to be coming up a ramp outside the door. I saw that I must finish Nastor quickly; but he proved a better swordsman than I had expected, although the encounter quickly developed into a foot race about the chamber.