Lampert shrugged and brought his full attention back to the controls. The sun was slowly sinking, bringing into bolder relief the irregularities of the ground as their shadows lengthened. However, these irregularities were still few, and the jungle roof was for the most part evenly illuminated. As McLaughlin had expected, there was nothing that could be used as a landmark. In its own way, the forest was as featureless as the ocean. The pilot kept his gaze riveted ahead, in expectation of the river which the guide had told them to expect; and presently he saw it. Reflecting the color of the faintly purplish sky, it stood out fairly well against the gray-green of the jungle, once they were close enough to penetrate the ever-present haze.
With McLaughlin nodding silent approval, Lampert swung the helicopter to the left and proceeded more nearly straight north, angling gradually toward the river. Now the jungle took on a little more feature, though still nothing that could be used for guidance. At fairly frequent intervals a glint of water became visible through the trees directly below them. Evidently numerous tributaries were feeding into the larger stream; but none of these could be seen from any distance. For the most part they were so narrow that the trees growing on each side met above them.
"I should think that one could cover a great deal of that territory in a boat," remarked Mitsuitei, after nearly half an hour in the new direction.
"You'd need an amphib," replied the guide. "A boat is all right for the main stream, but all that stuff coming in from the sides is so shallow that you'd never make progress with anything else. I've tried most of them in my own croc. Every time I've had to crawl rather than float before I was a mile from the river."
"How is the ground? Swamp?"
"No, it's fairly solid for the most part. It doesn't show very well yet even with the sun as low as it is, but the general ground level is pushing up slowly all along here. We'll be in sight of your mountains before too long."
This declaration brought all members of the group to the windows, all five pairs of eyes covering the quadrant of vision below and ahead. The meandering river was now on their left, but just visible through the haze ahead of them was the eastward turn McLaughlin had predicted. Lampert headed a little more to the right in an attempt to cut the final corner, but the helicopter reached the winding purplish band before their goal came in sight in spite of this effort. The flyer hummed on.
The bars of sunlight admitted by the side ports had been nearly horizontal when the turn to the east cut them off. They were only slightly more so when McLaughlin gave a satisfied grunt, and nodded forward. The others followed his gaze.
Straight ahead, little could be seen because of the "bright spot" familiar to every flyer—the shadowless area directly opposite the sun, centered on the aircraft's own shadow. To either side, however, the promised hills rose out of the jungle to heights exceeding the present flight altitude of the helicopter. Presumably the canyon from which the river was supposed to emerge lay in their path. So, at any rate, Lampert remarked; and McLaughlin confirmed him.