The spell that held Arnsen broke. He flung himself after her, too late. Already she was gone. But along the corridor jewels floated, bright, shining, alive.

And suddenly strong arms were around Arnsen. The face of O'Brien was before him. O'Brien, no longer wearing his space-suit, haggard, and yet aflame with a vital something that glowed in his dark eyes. O'Brien—laughing.

"Steve!" His voice shook. "So you followed me. I'm glad. Come in here—it's all right."

The energy went out of Arnsen, leaving him weak and exhausted. He cast one glance up the empty corridor and followed O'Brien through a cave-opening into a little room cut out of solid rock. He felt the other's fingers loosening his helmet, removing the bulky space-suit. Some remnant of caution returned.

"The oxygen—"

"There's air here. It's a place of wonders, Steve!"

There was air. Cool, sweet, and refreshing, it crept into Arnsen's lungs. He looked around. The little cavern was empty, save for dozens of the rainbow crystals clinging to the walls.

They watched alertly.

O'Brien pressed him back, made a quick gesture. A jewel floated forward, hovering over Arnsen's face. He felt water trickling between his lips, and, too exhausted for wonder, swallowed gratefully.

"You need sleep," O'Brien said. "But it's all right, Steve. It's all right, I tell you. You'll hear all about it when you wake up. Time enough then. You'll see Deirdre."