#underground river

Nearby a river thundered. A whirlpool seethed with frightening suction. Spume slashed in curtains. It was a merciless scene.

Except for the river sound and when they cried out from nightmares, their world grew still and quiet.

But then the river split into tributaries with tunnels feeding left and right. Beckwith chose one, and they followed that smaller river for several days until it, too, pronged left and right up a dozen different tubes.

The river flowed on, taking him around bends and crooks, away from danger.

Where the river widened, sometimes sprawling hundreds of meters across, the water seemed to stop and they sat nearly becalmed. At other times the river coursed powerfully. You could not call rapids what they occasionally ran. The water had a density to it, and the cascades poured with Amazon-like torpor.