In the event of absolute necessity, twelve men can operate the ship. That will leave fifteen to form a new searching party. Leaving me out, you would have fourteen, and after you have heard my plan, if you decide upon sending out such a party, I suggest that Lieutenant Dorf command it, leaving you, Captain Zuppner, and Hines to navigate the ship in the event that none of us returns, or that you finally decide to set out in search of us."

"But I thought that you were not going," said Zuppner.

"I am not going with the searching party. I am going alone in the scout plane, and my advice would be that you send out no searching party for at least twenty-four hours after I depart, for in that time I shall either have located those who are missing or have failed entirely."

Zuppner shook his head, dubiously. "Hines, Dorf and I have discussed the feasibility of using the scout plane," he said. "Hines was very anxious to make the attempt although he realizes better than any of us that once a pilot is out of sight of the O-220 he may never be able to locate it again, for you must remember that we know nothing concerning any of the landmarks of the country in the direction that our search must be prosecuted."

"I have taken all that into consideration," replied Gridley, "and I realize that it is at best but a forlorn hope."

"Let me undertake it," said Hines. "I have had more flying experience than any of you with the possible exception of Captain Zuppner, and it is out of the question that we should risk losing him."

"Any one of you three is probably better fitted to undertake such a flight than I," replied Gridley; "but that does not relieve me of the responsibility. I am more responsible than any other member of this party for our being where we are and, therefore, my responsibility for the safety of the missing members of the expedition is greater than that of any of the rest of you. Under the circumstances, then, I could not permit anyone else to undertake this flight. I think that you will all understand and appreciate how I feel and that you will do me the favor to interpose no more objection."

It was several minutes thereafter before anyone spoke, the four seeming to be immersed in the business of sipping their coffee and smoking their cigarettes. It was Zuppner who broke the silence.

"Before you undertake this thing," he said, "you should have a long sleep, and in the meantime we will get the plane out and have it gone over thoroughly. You must have every chance for success that we can give you."

"Thank you!" said Gridley. "I suppose you are right about the sleep. I hate to waste the time, but if you will call me the moment that the ship is ready I shall go to my cabin at once and get such sleep as I can in the meantime."

While Gridley slept, the scout plane, carried aft in the keel cabin, was lowered to the ground, where it underwent a careful inspection and test by the engineers and officers of the O-220.

Even before the plane was ready Gridley appeared at the cabin door of the O-220 and descended to the ground.

"You did not sleep long," said Zuppner.

"I do not know how long," said Gridley, "but I feel rested and anyway I could not have slept longer, knowing that those fellows are out there somewhere waiting and hoping for succor."

"What route do you expect to follow," asked Zuppner, "and how are you planning to insure a reasonable likelihood of your being able to return?"

"I shall fly directly over the forest as far as I think it at all likely that they could have marched in the time that they have been absent, assuming that they became absolutely confused and have traveled steadily away from the ship. As soon as I have gained sufficient altitude to make any observation I shall try and spot some natural landmark, like a mountain or a body of water, near the ship and from time to time, as I proceed, I shall make a note of similar landmarks, I believe that in this way I can easily find my way back, since at the furthest I cannot proceed over two hundred and fifty miles from the O-220 and return to it with the fuel that I can carry.

"After I have reached the furthest possible limits that I think the party could have strayed, I shall commence circling, depending upon the noise of the motor to attract their attention and, of course, assuming that they will find some means of signaling their presence to me, which they can do even in wooded country by building smudges."

"You expect to land?" inquired Zuppner, nodding at the heavy rifle which Gridley carried.

"If I find them in open country, I shall land; but even if I do not find them it may be necessary for me to come down and my recent experiences have taught me not to venture far in Pellucidar without a rifle."

After a careful inspection, Gridley shook hands with the three remaining officers and bid farewell to the ship's company, all of whom were anxious observers of his preparation for departure.

"Good-bye, old man," said Zuppner, "and may God and luck go with you."

Gridley pressed the hand of the man he had come to look upon as a staunch and loyal friend, and then took his seat in the open cockpit of the scout plane. Two mechanics spun the propeller, the motor roared and a moment later the block was kicked away and the plane rolled out across the grassy meadowland towards the forest at the far side. The watchers saw it rise swiftly and make a great circle and they knew that Gridley was looking for a landmark. Twice it circled above the open plain and then darted away across the forest.

It had not been until he made that first circle that Jason Gridley had realized the handicap that this horizonless landscape of Pellucidar had placed upon his chances of return. He had thought of a mountain standing boldly out against the sky, for such a landmark would have been almost constantly within the range of his vision during the entire flight.

There were mountains in the distance, but they stood out against no background or blue sky nor upon any horizon. They simply merged with the landscape beyond them, curving upward in the distance. Twice he circled, his keen eyes searching for any outstanding point in the topography of the country beneath him, but there was nothing that was more apparent than the grassy plain upon which the O-220 rested.

He felt that he could not waste time and fuel by searching longer for a landmark that did not exist, and while he realized that the plain would be visible for but a comparatively short distance he was forced to accept it as his sole guide in lieu of a better one.

Roaring above the leafy roof of the primeval forest, all that transpired upon the ground below was hidden from him and it was tantalizing to realize that he might have passed directly over the heads of the comrads he sought, yet there was no other way. Returning, he would either circle or hold an exaggerated zig-zag course, watching carefully for sign of a signal.

For almost two hours Jason Gridley held a straight course, passing over forest, plain and rolling, hilly country, but nowhere did he see any sign of those he sought. Already he had reached the limit of the distance he had planned upon coming when there loomed ahead of him in the distance a range of lofty mountains. These alone would have determined him to turn back, since his judgment told him that the lost members of the party, should they have chanced to come this far, would be now have realized that they were traveling in the wrong direction.

As he banked to turn he caught a glimpse out of the corner of an eye of something in the air above him and looking quickly back, Jason Gridley caught his breath in astonishment.

Hovering now, almost above him, was a gigantic creature, the enormous spread of those wings almost equalled that of the plane he was piloting. The man had a single glimpse of tremendous jaws, armed with mighty teeth, in the very instant that he realized that this mighty anachronism was bent upon attacking him.

Gridley was flying at an altitude of about three thousand feet when the huge pteranodon launched itself straight at the ship. Jason sought to elude it by diving. There was a terrific crash, a roar, a splintering of wood and a grinding of metal as the pteranodon swooped down upon its prey and full into the propeller.

What happened then, happened so quickly that Jason Gridley could not have reconstructed the scene five seconds later.

The plane turned completely over and at the same instant Gridley jumped. He jerked the rip cord of his parachute. Something struck him on the head and he lost consciousness.

Chapter 6 A PHORORHACOS OF THE MIOCENE

"WHERE ARE your people?" Tar-gash asked again.

Tarzan shook his head. "I do not know," he said.

"Where is your country?" asked Tar-gash.

"It is a long way off," replied the ape-man.