The nearness of the horizon bothered her. It didn't look right. She knew, consciously, that the Moon was only a quarter of the Earth's size and the horizon was therefore much closer than it would be on Earth. But still, at a deep, primitive level, it almost frightened her. As if there really was an edge to this barren, desolate world and she might drop off it.

Yeah, she told herself derisively, you're right in there with Columbus's crew. Sail on, babe. Sail on.

Doug didn't realize he still had the suit-to-suit frequency on until he started hearing strange sounds in his earphones. Gasps? Moans? The sounds came through for a moment, then disappeared, like ghosts vanishing into thin air.

Very thin air, around here, he told himself.

The rille had been getting progressively deeper, sinking more than four meters below the crater floor, Doug guessed.

It was hard to tell, and almost impossible to see if Gordette's boot prints were still marching along down there, even when he leaned carefully over the worn, rounded smooth edge of the rille to shine his helmet lamp on its bottom.

He came to a spot where a meteoroid had slammed into the ground just next to the rille, collapsing its side into a heap of rubble. Doug spent several minutes searching for bootprints; he found none. As far as he could see there were no prints on the other side of the narrow rille, either.

And the eerie sounds in his earphones had stopped, too.

I've overshot him, Doug told himself. He's back behind me someplace. Down inside the rille. Hiding.

Slowly, bending over the edge of the rille to examine its bottom, Doug started backtracking. He couldn't see the bottom of the arroyo, it was too deep for his helmet lamp to reach.

He stopped and listened. Nothing. Gordette had gone silent. Is he dead? Maybe what I heard was his last gasping for air.

With great reluctance, and more than a little fear, Doug carefully climbed down inside the rille, lowering himself slowly down as far as he could with his arms fully stretched, then letting himself slide the rest of the way down.

He felt the rough side wall grating against the chest of his suit. Couldn't do this in a fabric suit, he thought. The cermet won't tear. But he knew that grinding some dust or larger particles of grit into his suit's joints could immobilize him as thoroughly as the Tin Woodsman caught in a monsoon rain.

Doug had never felt the panic of claustrophobia, but as he stood shakily inside the narrow rille he saw that the sky above him was nothing more now than a constricted slice of stars cut off on both sides by the steep black walls of the arroyo. Like the view from the bottom of a grave, he thought.