It was simple enough. She slid the hatch shut and activated the pump. When the light turned green she opened the inner hatch and stepped into the shelter.

Doug was on the floor, his helmet off, pushing himself up onto his elbows.

"He wants to kill himself," Doug said to her. She barely heard him through her sealed helmet.

Sliding her visor up, she knelt beside Doug. "What happened? Are you all right?"

"He wants to kill himself," Doug repeated.

"Let him," she snapped. "Better him than you."

Slowly, Doug pushed himself to a sitting position, shook his head a few times, then started to clamber to his feet. "Where'd my helmet get to?" he mumbled.

"You're not going out there after him!"

He looked at her. "I can't let him die out there, Edith. He… I just can't."

I'll go with you, then."

"You stay here," Doug said firmly, walking back to pick his helmet off the floor. "You're a lot safer here inside the shelter."

"And you're going out to catch him?"

"To find him. To help him—if he'll let me."

"Not without me!"

"Yes, without you. You stay here. If I'm not back in an hour, get into the tractor and go back to Moonbase."

Edith started to argue, but one look into Doug's determined blue-gray eyes stopped her. It would be pointless, she knew.

So she waited ten minutes, by the watch on her spacesuit wrist, after Doug left the shelter. Then she went to the airlock and started after him in the tractor.

From her perch in the driver's seat she could see two pairs of bootprints clearly etched into the dark sandy ground. I won't need an Indian guide to help me follow their trail, Edith told herself.

DAY FORTY-FOUR

Doug followed Gordette's boot prints, gleaming bright and new in the ancient regolith. The only sounds he heard were his own breathing and the comforting soft buzz of the suit's air fans. He had stopped at the tractor to refill his air tank. Hunger gnawed at him but there was nothing he could do about that.

How much air does Bam have left in his suit? he wondered. How long can he roam around out here before he runs out?

Gordette's trail seemed to meander, with no specific aim or purpose. Doug followed it around a house-sized boulder, never even thinking that Gordette could be lurking behind the rock, waiting to ambush him. He wasn't. His boot prints skirted a worn old crater the size of a baseball diamond, and so deep that its bottom was lost in dense shadow. Meteroid must have come almost straight down to dig that one, Doug thought.

Soon, though, Gordette's trail started to run beside a sinuous rille that snaked along the dusty ground like an arroyo in desert country. Doug remembered his first walk out on the Moon's surface, his eighteenth birthday. With Foster Brennart. They had come across a rille that had suddenly spurted a ghostly cloud of gasses from deep within the lunar interior. Methane, ammonia, other volatiles. They had glittered in the sunlight like a billion fireflies.