"Can you use it?" I asked.

"I never have used one," she replied.

"Then give it to Llana of Gathol; she can use if it necessary, and very effectively too."

We approached to within about a hundred feet of the flier and stopped. This was the crucial moment; I was almost afraid to whistle, but I did. There was an immediate answer from the vicinity of the flier. I listened a moment for voices that might betray the presence of the enemy, but there were none.

We advanced quickly then, and I helped the girls over the rail. "Where are you, Ptor Fak?" I asked. "Are you alone?"

"On deck," he said, "and I don't think there is anyone around."

"All the warriors of Invak could be here now," I said, as I reached the controls and started the motor.

A moment later the little ship rose gracefully into the air, and almost immediately from below us, we heard shouts and imprecations. The Invaks had seen the ship, but too late to prevent our escape. We were safe. We had accomplished what a few hours before would have seemed impossible, for then Ptor Fak and I were chained to trees and Llana of Gathol was a captive in another part of the city.

"We owe Rojas a great debt of gratitude," I said.

"A debt," she replied, "which it will be very easy, and I hope pleasant, for you to repay."

I winced at that; I saw a bad time ahead for me. I would rather face a dozen men with my sword than one infuriated or heartbroken woman. Before we reached Helium, I would have to tell her; but I decided to wait until we had regained visibility.

Perhaps it would have been easier to tell her while we were both invisible, but it seemed a cowardly way to me.

"You are going on to Helium, John Carter?" asked Llana.

"Yes," I said.

"What will they think of a flier coming in by itself with no one on board?" she asked.

"We will have to wait until we become visible before we approach the city," I replied. "We must not take any more of the invisibility spheres."

"Who is John Carter?" asked Rojas. "Is there another here of whom I did not know?"

"I am John Carter," I replied. "Dotar Sojat is merely a name that I assumed temporarily."

"Then you are not the Sultan of Swat?" demanded Rojas.

"No," I replied, "I am not."

"You have deceived me."