So, in the end, all the adventurers save two took the sightseeing trip. Those two were Gary Lane and the elderly Eurasian scientist, Dr. Anjers, who had courteously excused himself.
"When one reaches my age, my friends, one loses interest in romantic surroundings. No, I shall remain here to be of what assistance I can to Dr. Lane."
And of assistance he was. For it was he whose adroit questioning of the Jovian engineers finally brought clarity to a question whose answer had been often hinted but never answered. As the workmen put the finishing touches on the warping unit's installation he asked, "And just what, gentlemen, are the limitations of this device ... the usage to which it may not safely be put? Your Councillor, Kushra, gave us to understand that there was a certain amount of peril inherent to its use."
The chief technician frowned. "That is right. However, we have taken all safety factors into consideration. In reaching your destination, if the dials and verniers are not changed from the settings which we have established, you will not experience the slightest difficulty—"
"But just what," asked Gary, "is the nature of this danger?"
"Simply that through an improper setting of the dials you might end your journey in some place quite unlike that which was your destination. In other words, if this central vernier were twisted to the right by so much as one degree the Liberty's flight might end not, as intended, within the solar galaxy of the star Sirius ... but within the burning heart of the star itself."
Gary frowned uneasily. "The only consolation to that thought is that if such a thing happened none of us would ever know anything about it."
"Quite true. The Liberty and all aboard would be instantaneously seared to a clinker by the inconceivable heat of a star thousands of times greater than our little sun."
"Why, then," asked Dr. Anjers, "employ control verniers at all? Why not simply set and lock the controls upon the desired objective?"