“What’s the idea?” Renny wanted to know.
“Some of the air to analyze later,” Doc explained. “This odor has me mystified.”
“To me, that melted rock is a bigger mystery,” Monk muttered. “And where’s my secretary? Where is everybody?”
Doc pointed at the patch of molten rock.
“Doesn’t the shape of that tell you something?”
Monk squinted.
“For cryin’ out loud!” he yelled. “That’s a door! And molten rock has oozed through from the other side, fillin’ it!”
“Exactly.”
“But what could have made heat enough to melt the rock like that?”
Doc did not answer. Instead, he rapped, “You birds look this place over! See what you can find!”
Then he was gone, vanishing with the speed and silence of a bronze apparition. A moment later, he was descending the cliff face.
Long Tom and Ham — guarding the planes — were not aware of his presence until he appeared phantom-like beside them.
“Heard anything?” he asked them.
“A minute ago,” Ham admitted. “I thought I heard a motor. But it might have been the sound of the river.”
“I don’t think it was,” Doc told him grimly.
He ran to the gyro, swung into the cockpit, and started the motor. He clutched in the rotary wing vanes as rapidly as possible, then bore heavily on the throttle. The strange ship lifted.
Although he had been within the cliff dwelling but a few minutes, the canyon depths were now a good deal less gloomy than before. The explanation was simple.
Dawn impended.
Doc guided the ship over the river and hovered there while he tossed out a flare. The light sank quickly into the stream.
But not before he made an interesting discovery.
Near the water’s edge, a slab of rock had been toppled back. It had uncovered the entrance of a tunnel, obviously man-made.
Doc wasted no time investigating except to note a large stake set near the water. To this, a boat had evidently been moored.
What had happened was clear. The builders of the ancient cliff dwelling had constructed the tunnel to give access to water when their stronghold was besieged. Down this, Doc’s enemies had fled to depart in the boat.
How they had closed the tunnel with molten rock was still a mystery — a puzzle Doc hoped to solve by analysis of the air he had trapped in the flask.
He flung the gyro downstream. Caution was necessary to avoid crashing into the canyon walls. It was doubtful if he made a great deal more speed than had the boat.
The darkness dispersed quickly. Dawn comes with suddenness in the clear, dry atmosphere of the West. He was able to increase his pace.
The river — rushing and angry — abruptly grew more peaceful. The canyon became less sheer, wider.
Then there was suddenly no canyon at all but a gently sloping valley. He was out of the range of mountains through which Red Skull slashed.
A bridge appeared. A graveled highway crossed it. Under the bridge, a large powerful launch was tied. The cowl and cushions of the boat were still wet with spray.
2 men stood on the bridge. They stared at the strange aircraft approaching them.
Doc landed on the road. He studied the 2 men as they approached.
One was stout and bulging of shoulder, big of hand. He would have been the better for a shave. His laced boots, khaki breeches, and leather windbreaker had seen much wear. He looked angry.
The second man’s attire was that of the city although his features were leathery from exposure to wind and sun. He had a reddish beard.
“If it isn’t one thing, it’s another!” the latter greeted Doc. “First, we’re robbed of our car. And then you come along in that contraption! What kind of a flyin’ machine is that, anyhow?”
Doc passed the question. “Did you get a look at the men who took your car?”
“Just at the one who held the gun. He was Buttons Zortell — a fellow we fired off the job some time ago. He made us lie in the ditch at the side of the road and we didn’t see the others. It sounded like there was quite a crowd, though. And I heard a woman’s voice. She seemed to be putting up a fight.”
This was welcome news for it meant Lea Aster was still alive.
“Who are you gentlemen?” Doc asked.
“I am Ossip Keller,” said the man in city garments. “My companion is my partner Richard O’Melia.”
“You men together with Nate Raff own the Mountain Desert Construction Company, don’t you?” Doc demanded.
“That’s right!”
Doc Savage gestured at the seat beside him.
“Get in. We’re going after your car. And the men who took it!”
The pair seemed a bit doubtful of the gyroplane.
“Will that thing carry us?”
“Of course. And it’s much safer than an ordinary plane if that’s worrying you.”
The two wedged into the seats. Doc promptly took off.
“The car went North toward our dam!” said Richard O’Melia in a gruff, roaring voice in keeping with his rough attire.
Doc drove the gyro forward at its maximum speed. Lifting their shouts over the noisy whine of the rotating wings and the shrill of the muffled motor, O’Melia and Keller explained their presence further.
“Our other partner Nate Raff was killed in a plane crash yesterday,” said O’Melia. “We got an early start this morning for we’ve got to go to the crash scene in New Mexico and see if we can identify Nate’s body. Everyone in the plane was badly burned.”
“And Buttons Zortell held us up on the bridge!” O’Melia thundered. “I’m bettin’ that’s got somethin’ to do with Nate’s death!”
“What do you mean?” Doc probed.
The men seemed reluctant to commit themselves.
“We suspect foul play in Nate’s death!” O’Melia boomed finally.
Ossip Keller now bent a keen-eyed stare on Doc. It was plain to be seen that he was a far more intelligent man than the blustering O’Melia.
“May I ask who you are?” he addressed Doc.
“My name is Savage.”
The effect of this was ludicrous. The jaws of both men sagged. They became round-eyed.
“Not Doc Savage?” O’Melia thundered.
“That’s right.”
“Glory be!” yelled O’Melia. “You’re the gent we’re wantin’ to see more’n anybody! When Nate Raff was killed, he was goin’ to New York to see you. We sent Bandy, too!”
“Who was Bandy Stevens?” Doc inquired.
“Didn’t Bandy manage to get to you?”
“He did… only to be killed before he could tell me anything.”
Ossip Keller now showed a trace of doubt, of suspicion.
“If Bandy did not talk to you, why are you here?”
“I’m here because a gang — apparently your enemies — are holding a young woman, the secretary of one of my men,” Doc explained grimly. “You haven’t told me who Bandy Stevens was.”
“One of our employees. A man we trusted,” Keller answered. “We sent Bandy to enlist your aid. Bandy wired us that some one had shot at him in Phoenix. That worried Nate Raff. So Nate lit out to see you himself. And the plane he was ridin’ in crashed.”
Doc had been keeping his eyes on the road below. There was plenty of light now although hills in the East still hid the Sun.
But no sign of the car could he discern.
“Suppose you gentlemen explain why you were trying to get in touch with me,” Doc suggested.
“We’ve been havin’ trouble with our dam buildin’,” thumped O’Melia. “And what trouble! You never saw the like! Rock slides, fatal accidents, equipment failures. Just about everything that could go wrong did!