ed at him. He was short, half a head shorter than she, but broad
and powerful as a man might be who had grown up in heavy gravity. He
trod the street with a light, controlled step, seeming to deliberately
hold himself down.

"If Dr. Mansard succeeded in landing on Jupiter, why didn't anyone ever
hear from him again?" she demanded.

"Because," said Quest, "his radio was sabotaged, just as his ship's
drive was."

"Jupiter strength," she murmured, looking him over coolly. "You wear
Motwick on your shoulder like a scarf. But you couldn't bring yourself
to help a woman against two thugs."

He flushed.

"I'm sorry," he said. "That's something I couldn't help."

"Why not?"

"I don't know. It's not that I'm afraid, but there's something in me
that makes me back away from the prospect of fighting anyone."

Trella sighed. Cowardice was a state of mind. It was peculiarly
inappropriate, but not unbelievable, that the strongest and most agile
man on Ganymede should be a coward. Well, she thought with a rush of
sympathy, he couldn't help being what he was.

* * * * *

They had reached the more brightly lighted section of the city now.
Trella could get a cab from here, but the Stellar Hotel wasn't far. They
walked on.

Trella had the desk clerk call a cab to deliver the unconscious Motwick
to his home. She and Quest had a late sandwich in the coffee shop.

"I landed here only a week ago," he told her, his eyes frankly admiring
her honey-colored hair and comely face. "I'm heading for Earth on the
next spaceship."

"We'll be traveling companions, then," she said. "I'm going back on that
ship, too."

For some reason she decided against telling him that the assignment on
which she had come to the Jupiter system was to gather his own father's
notebooks and take them back to Earth.

* * * * *

Motwick was an irresponsible playboy whom Trella had known briefly on
Earth, and Trella was glad to dispense with his company for the
remaining three weeks before the spaceship blasted off. She found
herself enjoying the steadier companionship of Quest.

As a matter of fact, she found herself enjoying his companionship more
than she intended to. She found herself falling in love with him.

Now this did not suit her at all. Trella had always liked her men tall
and dark. She had determined that when she married it would be to a
curly-haired six-