The chill dark of the tunnel mouth swallowed them. Keeping right to avoid the great copper posts that held the cables, strung through holes drilled in the solid rock of the gallery's outer wall, Gray urged the girl along.
The cleft his hand was searching for opened. Drawing the girl inside, around a jutting shoulder, he stopped, listening.
Footsteps echoed outside, grew louder, swept by. There was no light. But the steps were too sure to have been made in the dark.
"Infra-red torches and goggles," Gray said tersely, "You see, but your quarry doesn't. Useful gadget. Come on."
"But where? What are you going to do?"
"Escape, girl. Remember? They smashed my ship. But there must be another one on Mercury. I'm going to find it."
"I don't understand."
"You probably never will. Here's where I leave you. That Martian Galahad will be along any minute. He'll take you home."
Her voice came soft and puzzled through the dark.