I am forced to admit that even though I had traveled a long distance to place Bowen Tyler's manuscript in the hands of his father, I was still a trifle skeptical as to its sincerity, since I could not but recall that it had not been many years since Bowen had been one of the most notorious practical jokers of his alma mater. The truth was that as I sat in the Tyler library at Santa Monica I commenced to feel a trifle foolish and to wish that I had merely forwarded the manuscript by express instead of bearing it personally, for I confess that I do not enjoy being laughed at. I have a well-developed sense of humor--when the joke is not on me.

Mr. Tyler, Sr., was expected almost hourly. The last steamer in from Honolulu had brought information of the date of the expected sailing of his yacht Toreador, which was now twenty-four hours overdue. Mr. Tyler's assistant secretary, who had been left at home, assured me that there was no doubt but that the Toreador had sailed as promised, since he knew his employer well enough to be positive that nothing short of an act of God would prevent his doing what he had planned to do. I was also aware of the fact that the sending apparatus of the Toreador's wireless equipment was sealed, and that it would only be used in event of dire necessity. There was, therefore, nothing to do but wait, and we waited.

We discussed the manuscript and hazarded guesses concerning it and the strange events it narrated. The torpedoing of the liner upon which Bowen J. Tyler, Jr., had taken passage for France to join the American Ambulance was a well-known fact, and I had further substantiated by wire to the New York office of the owners, that a Miss La Rue had been booked for passage. Further, neither she nor Bowen had been mentioned among the list of survivors; nor had the body of either of them been recovered.

Their rescue by the English tug was entirely probable; the capture of the enemy U-33 by the tug's crew was not beyond the range of possibility; and their adventures during the perilous cruise which the treachery and deceit of Benson extended until they found themselves in the waters of the far South Pacific with depleted stores and poisoned water-casks, while bordering upon the fantastic, appeared logical enough as narrated, event by event, in the manuscript.

Caprona has always been considered a more or less mythical land, though it is vouched for by an eminent navigator of the eighteenth century; but Bowen's narrative made it seem very real, however many miles of trackless ocean lay between us and it. Yes, the narrative had us guessing. We were agreed that it was most improbable; but neither of us could say that anything which it contained was beyond the range of possibility. The weird flora and fauna of Caspak were as possible under the thick, warm atmospheric conditions of the super-heated crater as they were in the Mesozoic era under almost exactly similar conditions, which were then probably world-wide. The assistant secretary had heard of Caproni and his discoveries, but admitted that he never had taken much stock in the one nor the other. We were agreed that the one statement most difficult of explanation was that which reported the entire absence of human young among the various tribes which Tyler had had intercourse. This was the one irreconcilable statement of the manuscript. A world of adults! It was impossible.

We speculated upon the probable fate of Bradley and his party of English sailors. Tyler had found the graves of two of them; how many more might have perished! And Miss La Rue--could a young girl long have survived the horrors of Caspak after having been separated from all of her own kind? The assistant secretary wondered if Nobs still was with her, and then we both smiled at this tacit acceptance of the truth of the whole uncanny tale:

"I suppose I'm a fool," remarked the assistant secretary; "but by George, I can't help believing it, and I can see that girl now, with the big Airedale at her side protecting her from the terrors of a million years ago. I can visualize the entire scene--the apelike Grimaldi men huddled in their filthy caves; the huge pterodactyls soaring through the heavy air upon their bat-like wings; the mighty dinosaurs moving their clumsy hulks beneath the dark shadows of preglacial forests--the dragons which we considered myths until science taught us that they were the true recollections of the first man, handed down through countless ages by word of mouth from father to son out of the unrecorded dawn of humanity."

"It is stupendous--if true," I replied. "And to think that possibly they are still there--Tyler and Miss La Rue--surrounded by hideous dangers, and that possibly Bradley still lives, and some of his party! I can't help hoping all the time that Bowen and the girl have found the others; the last Bowen knew of them, there were six left, all told--the mate Bradley, the engineer Olson, and Wilson, Whitely, Brady and Sinclair. There might be some hope for them if they could join forces; but separated, I'm afraid they couldn't last long."

"If only they hadn't let the German prisoners capture the U-33! Bowen should have had better judgment than to have trusted them at all. The chances are von Schoenvorts succeeded in getting safely back to Kiel and is strutting around with an Iron Cross this very minute. With a large supply of oil from the wells they discovered in Caspak, with plenty of water and ample provisions, there is no reason why they couldn't have negotiated the submerged tunnel beneath the barrier cliffs and made good their escape."

"I don't like 'em," said the assistant secretary; "but sometimes you got to hand it to 'em."

"Yes," I growled, "and there's nothing I'd enjoy more than handing it to them!" And then the telephone-bell rang.

The assistant secretary answered, and as I watched him, I saw his jaw drop and his face go white. "My God!" he exclaimed as he hung up the receiver as one in a trance. "It can't be!"

"What?" I asked.

"Mr. Tyler is dead," he answered in a dull voice. "He died at sea, suddenly, yesterday."

The next ten days were occupied in burying Mr. Bowen J. Tyler, Sr., and arranging plans for the succor of his son. Mr. Tom Billings, the late Mr. Tyler's secretary, did it all. He is force, energy, initiative and good judgment combined and personified. I never have beheld a more dynamic young man. He handled lawyers, courts and executors as a sculptor handles his modeling clay. He formed, fashioned and forced them to his will. He had been a classmate of Bowen Tyler at college, and a fraternity brother, and before, that he had been an impoverished and improvident cow-puncher on one of the great Tyler ranches. Tyler, Sr., had picked him out of thousands of employees and made him; or rather Tyler had given him the opportunity, and then Billings had made himself. Tyler, Jr., as good a judge of men as his father, had taken him into his friendship, and between the two of them they had turned out a man who would have died for a Tyler as quickly as he would have for his flag. Yet there was none of the sycophant or fawner in Billings; ordinarily I do not wax enthusiastic about men, but this man Billings comes as close to my conception of what a regular man should be as any I have ever met. I venture to say that before Bowen J. Tyler sent him to college he had never heard the word ethics, and yet I am equally sure that in all his life he never has transgressed a single tenet of the code of ethics of an American gentleman.

Ten days after they brought Mr. Tyler's body off the Toreador, we steamed out into the Pacific in search of Caprona. There were forty in the party, including the master and crew of the Toreador; and Billings the indomitable was in command. We had a long and uninteresting search for Caprona, for the old map upon which the assistant secretary had finally located it was most inaccurate. When its grim walls finally rose out of the ocean's mists before us, we were so far south that it was a question as to whether we were in the South Pacific or the Antarctic. Bergs were numerous, and it was very cold.

All during the trip Billings had steadfastly evaded questions as to how we were to enter Caspak after we had found Caprona. Bowen Tyler's manuscript had made it perfectly evident to all that the subterranean outlet of the Caspakian River was the only means of ingress or egress to the crater world beyond the impregnable cliffs. Tyler's party had been able to navigate this channel because their craft had been a submarine; but the Toreador could as easily have flown over the cliffs as sailed under them. Jimmy Hollis and Colin Short whiled away many an hour inventing schemes for surmounting the obstacle presented by the barrier cliffs, and making ridiculous wagers as to which one Tom Billings had in mind; but immediately we were all assured that we had raised Caprona, Billings called us together.

"There was no use in talking about these things," he said, "until we found the island. At best it can be but conjecture on our part until we have been able to scrutinize the coast closely. Each of us has formed a mental picture of the Capronian seacoast from Bowen's manuscript, and it is not likely that any two of these pictures resemble each other, or that any of them resemble the coast as we shall presently find it. I have in view three plans for scaling the cliffs, and the means for carrying out each is in the hold. There is an electric drill with plenty of waterproof cable to reach from the ship's dynamos to the cliff-top when the Toreador is anchored at a safe distance from shore, and there is sufficient half-inch iron rod to build a ladder from the base to the top of the cliff. It would be a long, arduous and dangerous work to bore the holes and insert the rungs of the ladder from the bottom upward; yet it can be done.

"I also have a life-saving mortar with which we might be able to throw a line over the summit of the cliffs; but this plan would necessitate one of us climbing to the top with the chances more than even that the line would cut at the summit, or the hooks at the upper end would slip.

"My third plan seems to me the most feasible. You all saw a number of large, heavy boxes lowered into the hold before we sailed. I know you did, because you asked me what they contained and commented upon the large letter 'H' which was painted upon each box. These boxes contain the various parts of a hydro-aeroplane. I purpose assembling this upon the strip of beach described in Bowen's manuscript--the beach where he found the dead body of the apelike man--provided there is sufficient space above high water; otherwise we shall have to assemble it on deck and lower it over the side. After it is assembled, I shall carry tackle and ropes to the cliff-top, and then it will be comparatively simple to hoist the search-party and its supplies in safety. Or I can make a sufficient number of trips to land the entire party in the valley beyond the barrier; all will depend, of course, upon what my first reconnaissance reveals."

That afternoon we steamed slowly along the face of Caprona's towering barrier.

"You see now," remarked Billings as we craned our necks to scan the summit thousands of feet above us, "how futile it would have been to waste our time in working out details of a plan to surmount those." And he jerked his thumb toward the cliffs. "It would take weeks, possibly months, to construct a ladder to the top. I had no conception of their formidable height. Our mortar would not carry a line halfway to the crest of the lowest point. There is no use discussing any plan other than the hydro-aeroplane. We'll find the beach and get busy."

Late the following morning the lookout announced that he could discern surf about a mile ahead; and as we approached, we all saw the line of breakers broken by a long sweep of rolling surf upon a narrow beach. The launch was lowered, and five of us made a landing, getting a good ducking in the ice-cold waters in the doing of it; but we were rewarded by the finding of the clean-picked bones of what might have been the skeleton of a high order of ape or a very low order of man, lying close to the base of the cliff. Billings was satisfied, as were the rest of us, that this was the beach mentioned by Bowen, and we further found that there was ample room to assemble the sea-plane.

Billings, having arrived at a decision, lost no time in acting, with the result that before mid-afternoon we had landed all the large boxes marked "H" upon the beach, and were busily engaged in opening them. Two days later the plane was assembled and tuned. We loaded tackles and ropes, water, food and ammunition in it, and then we each implored Billings to let us be the one to accompany him. But he would take no one. That was Billings; if there was any especially difficult or dangerous work to be done, that one man could do, Billings always did it himself. If he needed assistance, he never called for volunteers--just selected the man or men he considered best qualified for the duty. He said that he considered the principles underlying all volunteer service fundamentally wrong, and that it seemed to him that calling for volunteers reflected upon the courage and loyalty of the entire command.

We rolled the plane down to the water's edge, and Billings mounted the pilot's seat. There was a moment's delay as he assured himself that he had everything necessary. Jimmy Hollis went over his armament and ammunition to see that nothing had been omitted. Besides pistol and rifle, there was the machine-gun mounted in front of him on the plane, and ammunition for all three. Bowen's account of the terrors of Caspak had impressed us all with the necessity for proper means of defense.

At last all was ready. The motor was started, and we pushed the plane out into the surf. A moment later, and she was skimming seaward. Gently she rose from the surface of the water, executed a wide spiral as she mounted rapidly, circled once far above us and then disappeared over the crest of the cliffs. We all stood silent and expectant, our eyes glued upon the towering summit above us. Hollis, who was now in command, consulted his wrist-watch at frequent intervals.

"Gad," exclaimed Short, "we ought to be hearing from him pretty soon!"

Hollis laughed nervously. "He's been gone only ten minutes," he announced.

"Seems like an hour," snapped Short. "What's that? Did you hear that? He's firing! It's the machine-gun! Oh, Lord; and here we are as helpless as a lot of old ladies ten thousand miles away! We can't do a thing. We don't know what's happening. Why didn't he let one of us go with him?"

Yes, it was the machine-gun. We would hear it distinctly for at least a minute. Then came silence. That was two weeks ago. We have had no sign nor signal from Tom Billings since.