Guardsmen and nobles pressed close about the silent witness upon the marble floor. Many were the exclamations of astonishment and questioning wonder as Xodar's acts confirmed the suspicion which he had held.

"A thern!" whispered Tars Tarkas.

"Worse than that, I fear," replied Xodar. "But let us see."

With that he drew his dagger and cut open a locked pouch which had dangled from the thern's harness, and from it he brought forth a circlet of gold set with a large gem-it was the mate to that which I had taken from Sator Throg.

"He was a Holy Thern," said Xodar. "Fortunate indeed it is for us that he did not escape."

The officer of the guard entered the chamber at this juncture.

"My Prince," he said, "I have to report that this fellow's companion escaped us. I think that it was with the connivance of one or more of the men at the gate. I have ordered them all under arrest."

Xodar handed him the thoat oil and cloth.

"With this you may discover the spy among you," he said.

I at once ordered a secret search within the city, for every Martian noble maintains a secret service of his own.

A half-hour later the officer of the guard came again to report. This time it was to confirm our worst fears-half the guards at the gate that night had been therns disguised as red men.

"Come!" I cried. "We must lose no time. On to Hastor at once. Should the therns attempt to check us at the southern verge of the ice cap it may result in the wrecking of all our plans and the total destruction of the expedition."

Ten minutes later we were speeding through the night toward Hastor, prepared to strike the first blow for the preservation of Dejah Thoris.

Two hours after leaving my palace at Helium, or about midnight, Kantos Kan, Xodar, and I arrived at Hastor. Carthoris, Tars Tarkas, and Hor Vastus had gone directly to Thark upon another cruiser.

The transports were to get under way immediately and move slowly south. The fleet of battleships would overtake them on the morning of the second day.

At Hastor we found all in readiness, and so perfectly had Kantos Kan planned every detail of the campaign that within ten minutes of our arrival the first of the fleet had soared aloft from its dock, and thereafter, at the rate of one a second, the great ships floated gracefully out into the night to form a long, thin line which stretched for miles toward the south.

It was not until after we had entered the cabin of Kantos Kan that I thought to ask the date, for up to now I was not positive how long I had lain in the pits of Zat Arras. When Kantos Kan told me, I realized with a pang of dismay that I had misreckoned the time while I lay in the utter darkness of my cell. Three hundred and sixty-five days had passed-it was too late to save Dejah Thoris.

The expedition was no longer one of rescue but of revenge. I did not remind Kantos Kan of the terrible fact that ere we could hope to enter the Temple of Issus, the Princess of Helium would be no more. In so far as I knew she might be already dead, for I did not know the exact date on which she first viewed Issus.

What now the value of burdening my friends with my added personal sorrows-they had shared quite enough of them with me in the past. Hereafter I would keep my grief to myself, and so I said nothing to any other of the fact that we were too late. The expedition could yet do much if it could but teach the people of Barsoom the facts of the cruel deception that had been worked upon them for countless ages, and thus save thousands each year from the horrid fate that awaited them at the conclusion of the voluntary pilgrimage.

If it could open to the red men the fair Valley Dor it would have accomplished much, and in the Land of Lost Souls between the Mountains of Otz and the ice barrier were many broad acres that needed no irrigation to bear rich harvests.

Here at the bottom of a dying world was the only naturally productive area upon its surface. Here alone were dews and rains, here alone was an open sea, here was water in plenty; and all this was but the stamping ground of fierce brutes and from its beauteous and fertile expanse the wicked remnants of two once mighty races barred all the other millions of Barsoom. Could I but succeed in once breaking down the barrier of religious superstition which had kept the red races from this El Dorado it would be a fitting memorial to the immortal virtues of my Princess-I should have again served Barsoom and Dejah Thoris' martyrdom would not have been in vain.

On the morning of the second day we raised the great fleet of transports and their consorts at the first flood of dawn, and soon were near enough to exchange signals. I may mention here that radio-aerograms are seldom if ever used in war time, or for the transmission of secret dispatches at any time, for as often as one nation discovers a new cipher, or invents a new instrument for wireless purposes its neighbours bend every effort until they are able to intercept and translate the messages. For so long a time has this gone on that practically every possibility of wireless communication has been exhausted and no nation dares transmit dispatches of importance in this way.

Tars Tarkas reported all well with the transports. The battleships passed through to take an advanced position, and the combined fleets moved slowly over the ice cap, hugging the surface closely to prevent detection by the therns whose land we were approaching.

Far in advance of all a thin line of one-man air scouts protected us from surprise, and on either side they flanked us, while a smaller number brought up the rear some twenty miles behind the transports. In this formation we had progressed toward the entrance to Omean for several hours when one of our scouts returned from the front to report that the cone-like summit of the entrance was in sight. At almost the same instant another scout from the left flank came racing toward the flagship.

His very speed bespoke the importance of his information. Kantos Kan and I awaited him upon the little forward deck which corresponds with the bridge of earthly battleships. Scarcely had his tiny flier come to rest upon the broad landing-deck of the flagship ere he was bounding up the stairway to the deck where we stood.

"A great fleet of battleships south-south-east, my Prince," he cried. "There must be several thousands and they are bearing down directly upon us."

"The thern spies were not in the palace of John Carter for nothing," said Kantos Kan to me. "Your orders, Prince."

"Dispatch ten battleships to guard the entrance to Omean, with orders to let no hostile enter or leave the shaft. That will bottle up the great fleet of the First Born.

"Form the balance of the battleships into a great V with the apex pointing directly south-south-east. Order the transports, surrounded by their convoys, to follow closely in the wake of the battleships until the point of the V has entered the enemies' line, then the V must open outward at the apex, the battleships of each leg engage the enemy fiercely and drive him back to form a lane through his line into which the transports with their convoys must race at top speed that they may gain a position above the temples and gardens of the therns.

"Here let them land and teach the Holy Therns such a lesson in ferocious warfare as they will not forget for countless ages. It had not been my intention to be distracted from the main issue of the campaign, but we must settle this attack with the therns once and for all, or there will be no peace for us while our fleet remains near Dor, and our chances of ever returning to the outer world will be greatly minimized."

Kantos Kan saluted and turned to deliver my instructions to his waiting aides. In an incredibly short space of time the formation of the battleships changed in accordance with my commands, the ten that were to guard the way to Omean were speeding toward their destination, and the troopships and convoys were closing up in preparation for the spurt through the lane.