Another five minutes found us at the edge of the stream, which at that point was much swifter than it was farther up. We waded in and discovered that the cause was its extreme narrowness.
"But where does the thing go to?" asked Harry, taking the words from my mouth.
We soon found out. Proceeding along the bank to the left, within fifty feet we came to the wall. There the stream entered and disappeared. But, unlike the others we had seen, above this there was a wide and high arch, which made it appear as though the stream were passing under a massive bridge. The current was swift but not turbulent, and there was something about the surface of that stream flowing straight through the mountain ahead of us—
Harry and I glanced at each other quickly, moved by the same thought. There was an electric thrill in that glance.
But we did not speak—then.
For suddenly, startlingly, a voice sounded throughout the cavern—Desiree's voice, raised in a shrill cry of terror.
It was repeated twice before our startled senses found themselves; then we turned with one impulse and raced into the darkness toward her.