"This is undoubtedly a newer planet than ours. I should say that it was in the Carboniferous age. Aren't those trees like those in the coal-measures, Seaton?"

"True as time, Blackie--there probably won't be a human race here for ages, unless we bring out some colonists."

Seaton kicked at one of the loose lumps of metal questioningly with his heavy shoe, finding that it was as immovable as though it were part of the ledge. Bending over, he found that it required all his great strength to lift it and he stared at it with an expression of surprise, which turned to amazement as he peered closer.

"DuQuesne! Look at this!"

DuQuesne studied the metal, and was shaken out of his habitual taciturnity.

"Platinum, by all the little gods!"

"We'll grab some of this while the grabbing's good," announced Seaton, and the few visible lumps were rolled into the car. "If we had a pickaxe we could chop some more off one of those sharp ledges down there."

"There's an axe in the shop," replied DuQuesne. "I'll go get it. Go ahead, I'll soon be with you."

"Keep close together," warned Crane as the four moved slowly down the slope. "This is none too safe, Dick."

"No, it isn't, Mart. But we've got to see whether we can't find some copper, and I would like to get some more of this stuff, too. I don't think it's platinum, I believe that it's X."

As they reached the broken projections, Margaret glanced back over her shoulder and screamed. The others saw that her face was white and her eyes wide with horror, and Seaton instinctively drew his pistol as he whirled about, only to check his finger on the trigger and lower his hand.

"Nothing but X-plosive bullets," he growled in disgust, and in helpless silence the four watched an unspeakably hideous monster slowly appear from behind the Skylark. Its four huge, squat legs supported a body at least a hundred feet long, pursy and ungainly; at the extremity of a long and sinuous neck a comparatively small head seemed composed entirely of a cavernous mouth armed with row upon row of carnivorous teeth. Dorothy gasped with terror and both girls shrank closer to the two men, who maintained a baffled silence as the huge beast passed his revolting head along the hull of the vessel.

"I dare not shoot, Martin," Seaton whispered, "it would wreck the bus.

Have you got any solid bullets?"

"No. We must hide behind these small ledges until it goes away,"

answered Crane, his eyes upon Margaret's colorless face. "You two hide behind that one, we will take this one."

"Oh, well, it's nothing to worry about, anyway. We can kill him as soon as he gets far enough away from the boat," said Seaton as, with Dorothy clinging to him, he dropped behind one of the ledges. Margaret, her staring eyes fixed upon the monster, remained standing until Crane touched her gently and drew her down beside him.

"He will go away soon," his even voice assured her. "We are in no danger."

In spite of their predicament, a feeling of happiness flowed through Crane's whole being as he crouched beside the wall of metal with one arm protectingly around Margaret, and he longed to protect her through life as he was protecting her then. Accustomed as he was to dangerous situations, he felt no fear. He felt only a great tenderness for the girl by his side, who had ceased trembling but was still staring wide-eyed at the monster through a crevice.

"Scared, Peggy?" he whispered.

"Not now, Martin, but if you weren't here I would die of fright."

At this reply his arm tightened involuntarily, but he forced it to relax.

"It will not be long," he promised himself silently, "until she is back at home among her friends, and then...."

There came the crack of a rifle from the Skylark. There was an awful roar from the dinosaur, which was quickly silenced by a stream of machine-gun bullets.

"Blackie's on the job--let's go!" cried Seaton, and they raced up the slope. Making a detour to avoid the writhing and mutilated mass they plunged through the opening door. DuQuesne shut it behind them and in overwhelming relief, the adventurers huddled together as from the wilderness without there arose an appalling tumult.

The scene, so quiet a few moments before, was instantly changed. The trees, the swamp, and the air seemed filled with monsters so hideous as to stagger the imagination. Winged lizards of prodigious size hurtled through the air, plunging to death against the armored hull.

Indescribable flying monsters, with feathers like birds, but with the fangs of tigers, attacked viciously. Dorothy screamed and started back as a scorpion-like thing with a body ten feet in length leaped at the window in front of her, its terrible sting spraying the glass with venom. As it fell to the ground, a huge spider--if an eight-legged creature with spines instead of hair, many-faceted eyes, and a bloated, globular body weighing hundreds of pounds, may be called a spider--leaped upon it and, mighty mandibles against poisonous sting, the furious battle raged. Several twelve-foot cockroaches climbed nimbly across the fallen timber of the morass and began feeding voraciously upon the body of the dead dinosaur, only to be driven away by another animal, which all three men recognized instantly as that king of all prehistoric creatures, the saber-toothed tiger. This newcomer, a tawny beast towering fifteen feet high at the shoulder, had a mouth disproportionate even to his great size--a mouth armed with four great tiger-teeth more than three feet in length. He had barely begun his meal, however, when he was challenged by another nightmare, a something apparently half-way between a dinosaur and a crocodile. At the first note the tiger charged. Clawing, striking, rending each other with their terrible teeth, a veritable avalanche of bloodthirsty rage, the combatants stormed up and down the little island. But the fighters were rudely interrupted, and the earthly visitors discovered that in this primitive world it was not only animal life that was dangerous.

[Illustration: The great tree standing on the farther edge of the island suddenly bent over, lashing out like a snake and grasping both. It transfixed them with the terrible thorns, which were now seen to be armed with needlepoints and to possess barbs like fish-hooks.]

The great tree standing on the farther edge of the island suddenly bent over, lashing out like a snake and grasping both. It transfixed them with the terrible thorns, which were now seen to be armed with needlepoints and to possess barbs like fish-hooks. It ripped at them with the long branches, which were veritable spears. The broad leaves, armed with revolting sucking disks, closed about the two animals, while the long, slender twigs, each of which was now seen to have an eye at its extremity, waved about, watching each movement of the captives from a safe distance.

If the struggle between the two animals had been awful, this was Titanic. The air was torn by the roars of the reptile, the screams of the great cat, and the shrieks of the tree. The very ground rocked with the ferocity of the conflict. There could be but one result--soon the tree, having absorbed the two gladiators, resumed its upright position in all its beauty.

The members of the little group stared at each other, sick at heart.

"This is NO place to start a copper-mine. I think we'd better beat it,"

remarked Seaton presently, wiping drops of perspiration from his forehead.

"I think so," acquiesced Crane. "We found air and Earth-like conditions here; we probably will elsewhere."

"Are you all right, Dottie?" asked Seaton.

"All right, Dicky," she replied, the color flowing back into her cheeks.

"It scared me stiff, and I think I have a lot of white hairs right now, but I wouldn't have missed it for anything."

She paused an instant, and continued:

"Dick, there must be a queer streak of brutality in me, but would you mind blowing up that frightful tree? I wouldn't mind its nature if it were ugly--but look at it! It's so deceptively beautiful! You wouldn't think it had the disposition of a fiend, would you?"

A general laugh relieved the nervous tension, and Seaton stepped impulsively toward DuQuesne with his hand outstretched.

"You've squared your account, Blackie. Say the word and the war's all off."

DuQuesne ignored the hand and glanced coldly at the group of eager, friendly faces.

"Don't be sentimental," he remarked evenly as he turned away to his room. "Emotional scenes pain me. I gave my word to act as one of the party."

"Well, may I be kicked to death by little red spiders!" exclaimed Seaton, dumbfounded, as the other disappeared. "He ain't a man, he's a fish!"

"He's a machine. I always thought so, and now I know it," stated Margaret, and the others nodded agreement.

"Well, we'll sure pull his cork as soon as we get back!" snapped Seaton.

"He asked for it, and we'll give him both barrels!"

"I know I acted the fool out there," Margaret apologized, flushing hotly and looking at Crane. "I don't know what made me act so stupid. I used to have a little nerve."

"You were a regular little brick, Peg," Seaton returned instantly. "Both you girls are all to the good--the right kind to have along in ticklish places."

Crane held out his steady hand and took Margaret's in a warm clasp.