The plane dipped. Down and ahead was a bare rock patch, not too even, looking like a handkerchief laid in the surrounding immensity of the wilderness.
Tensity held the others. It was impossible for a man to set a plane down on that rough rock surface, in the dim gray of early dawn. They clutched their seats.
But Benson did it. His pale, infallible eyes saw the spot like a camera, and remembered each rough outcropping so that when the wheels touched he could line them along the smoother ridges though he could no longer see them.
“Camouflage,” Benson ordered, as they got out in the cool dawn.
There were two small axes. Smitty and MacMurdie took them, cut bales of branches from saplings and big-leafed plants nearby, and strewed them over the plane so it could not be spotted from the air.
Benson and Chandler looked at the high wall of the ridge, just ahead of them, with the great natural figure of a grotesque human looming at the top. Then they looked once more at a sheet of paper Benson spread out. On the sheet were co-ordinated all the hieroglyphs of the three plates of Professor Gray and Alec Knight.
“We must be close to the cache right now,” Chandler said in a low, awed tone.
“You think it’s on this side of the ridge?” said Benson, pale and deadly eyes on the almost unscalable wall up to the huge figure.
“I’m sure of it,” said Chandler. “Look. The last symbol we have here is one for the setting sun. It comes right after the ideograph representing that statue. It must mean that the spot described in the next plate — which we haven’t got — is on the afternoon side, this side, of the ridge. At the statue’s right hand, so to speak.”
“I have an idea about that,” said Benson. “I’ll outline it a little later. In about,”—he stared at the pink sky eastward—“an hour and a half. Is this where you all camped on Gray’s last expedition?”
Chandler shook his head. “They found the tomb of Montezuma the Second far northwest of here. This particular locality is strange to me.”
Nellie Gray had been wandering at a little distance. She came up, trim in riding breeches and khaki shirt.
“We’ve hidden the plane,” she said. “Don’t you think we ought to hide ourselves, too? The gang may be here any minute.”
Benson nodded.
“There’s a thick grove, over there. We’ll have some breakfast in it. Watch out for snakes. The boas get pretty big in this section.”
“I’d rather see a hundred boas than Borg and his men,” said Nellie with a little shiver. “When we face them I want to be way behind the rest of you!”
She stared at the high ridge, like a two-mile wall before them. And it was too bad the wall wasn’t made of glass, so they could see the other side.
Borg, the ratlike brothers, the man with the reddish hair, a big fellow with a twisted nose, and three Indians as vicious-looking as any of the white men, were over there. The big fellow with the twisted nose was preparing to light a fire, over which some food would be prepared.
A fourth Indian slid into their camp. He said something in dialect. One of the other Indians interpreted to Borg.
“He say, they come. Big bird like your bird come down quiet like hawk on other side of wall. Four men and a woman. One man with old, old hair, but man young.”
“Benson!” exclaimed Borg with a satisfied oath. “We’ve got ’em now. We’ll leave them down here for the ants to feed on when we go north with the first load of that gold.” He stared at the man with the reddish hair. “Come on, Pete. You and me’ll take a little trip around the ridge with the guide. And the rest of you — no fire. The smoke could be seen. Eat your grub cold.”
The three set out through the low but almost impenetrable jungle, with the Indian gliding ahead. It took them nearly an hour and a half to get around the ridge and near the small cleared space on which was Benson’s plane.
In their close-covered glade, Benson was staring at the rising sun. More particularly, he was staring at a long shadow cast by the sun — a shadow cast by the great rock shaft atop the ridge.
“Secret hiding places for treasure fall into patterns,” he said, lambent gray eyes watching the creeping shadow of the shaft. “About half the time a central object is used for the starting point of measurements one way or another. The other half — the shadow cast by the conspicuous object — points to the cache. We’ll try that method now.”
“But we’re after that gang, not treasure,” said Nellie.
“By locating the treasure, we can ambush the gang with the most chance of success,” said Benson. “We’ll go to the end of the shaft’s shadow, and follow it as it shortens under the rising sun.”
They walked slowly after the shortening shadow, in a line, watching for any sign of man’s age-old handicraft in the thick tropic growth. Spiders as big as a man’s fist peered at them from red and gray-barked trees. Tiny lizards scuttled carefully out of reach of the spiders.
There was a low mound with trees all over it and a small sunken area in front of it. The shadow led them to this mound, and Smitty stumbled over something and almost fell.
The thing that had caught his feet was a stone, lichen-covered. But it was a peculiarly regular, square stone.
Benson stared at the mound. “This is it, I think.” He dug a little, parting overhanging roots. A hole appeared.
“All that’s left of an ancient door.”
He squeezed in. The others followed, with eyes shining and breath coming fast. Benson had his flashlight going.
A rough, crude hole was the entrance here. But once inside, the roughness and crudity disappeared. They were in a stone chamber, perfectly preserved, at least twelve feet high and thirty square — part of an old temple.
From this chamber led four openings. Benson went to one after another of them, playing his flash. The light went on and on down each, showing no end.
“Which?” said the giant Smitty.
“I’m thinkin’ we’d better take no one of them till we have a ball of yarn,” said MacMurdie dourly. “Whoosh! ’Tis a labyrinth we’re in!”
“He’s right,” said Chandler. “We’d better not go down any of those black holes too far.”
Benson paced to the center of the chamber.
“Your flashlight, Nellie.”
He set Nellie’s light on end, with the white beam playing up on the dimly carved ceiling.
“Now, we’ll go down one after another till we lose the light. At that point we’ll stop, assuming the tunnels themselves haven’t already stopped.”
In the side wall of the old temple room there was a rock, a little rougher than the surrounding dressed stone, sticking out several inches. Nellie was looking at it, and her hand went out.
“Don’t touch it!”
Benson’s voice was like a whiplash. Nellie drew her hand back from the rock and stared at him in surprise. Benson said, less urgently:
“It’s known that the Aztecs left clever and deadly traps for enemy raiders. Touch an innocent-looking stone outcropping, and tons of rock are released by a lever action to crush you. Or the floor falls away from you. Or a chasm opens under your feet. They were pretty good engineers, the old Aztecs. They knew their weights and counterweights. It might mean nothing to touch that stone knob — or it might bring the whole roof down on us.”
Nellie retreated hurriedly from the projection. Benson went on.
“You stay here with the light. Mac, take the tunnel in the left wall. Smitty, the one in the right. I’ll take the left rear tunnel; Chandler, the right rear. Anyone finding anything, call out. But not too loudly! Sound vibration might bring this old temple down around our ears.”