The locking ring was firmly welded to its flex tube and duly examined for flaws by eye, hologram scan, eddy current, the examination and comparison of the simultaneous x-ray emission recording, and the classic kick-and-jerk test. Leo prepared to move his students on to the next task.

"Tony, you bring the beam welder over—TURN IT OFF FIRST!" Feedback squeal lanced through everyone's earphones, and Leo modulated his voice from his first urgent panicked bellow. The beam had in fact been off, but the controls live; one accidental bump, as Tony swung the machine around, and—Leo's eye traced the hypothetical slice through the nearby wing of the Habitat, and he shuddered.

"Get your head out of your ass, Tony! I saw a man cut in half by one of his friends once by just that careless trick."

"Sorry . . . thought it would save time . . . sorry . . ." Tony mumbled.

"You know better." Leo calmed, as his heart stopped palpitating. "In this hard vacuum that beam won't stop till it hits the third moon, or whatever it might encounter in between." He almost continued, stopped himself; no, not over the public com channel. Later.

Later, as his students unsuited in the equipment locker, laughing and joking as they cleaned and stored their work suits, Leo drifted over to the silent and pale Tony. Surely I didn't bark at him that hard, Leo thought to himself. Figured he was more resilient . . . "Stop and see me when you're finished here," said Leo quietly.

Tony flinched guiltily. "Yes, sir."

After his fellows had all swooped out, eager for their end-of-shift meal, Tony hung in the air, both sets of arms crossed protectively across his torso. Leo floated near, and spoke in a grave tone.

"Where were you, out there today?"

"Sorry, sir. It won't happen again."

"It's been happening all week. You got something on your mind, boy?"

Tony shook his head. "Nothing—nothing to do with you, sir."

Meaning, nothing to do with work, Leo interpreted that. All right, so. "If it's taking your mind off your work, it does have something to do with me. Want to talk about it? You got girl trouble? Little Andy all right? You have a fight with somebody?"

Tony's blue eyes searched Leo's face in sudden uncertainty, then he grew closed and inward once again. "No, sir."

"You worried about going out on that contract? I guess it will be the first time away from home for you kids, at that."

"It's not that," denied Tony. He paused, watching Leo again. "Sir—are there a great many other companies out there besides ours?"