As the story opens, a starved, scared young boy is being sold on an auction block on a faraway planet. He is purchased by an old, one-eyed, one-legged man named Baslim. He appears to be a simple beggar, but is later revealed to be an anti-slavery agent (with a long history of heroism) who is working undercover.

Baslim raises the boy, Thorby, as his own son, nurturing and educating him. Through Baslim, Thorby receives an exceptional education atypical of the slave of a lowly beggar on an isolated planet. Baslim, aware that this education will not help him on a world where social mobility is very limited, begins arranging for Thorby's future, of which the boy is only partially aware.

When his espionage activities are eventually discovered by the harsh, autocratic government of the planet Sargon, Baslim winds up dead. Thorby, who knows very little of Baslim's covert activities, is wanted by the authorities for questioning, and goes into hiding. Fortunately for Thorby, this adoptive father had arranged before his death for Thorby to leave the planet Jubbul on a Free Trader ship.

Thus, Thorby safely escapes the planet Jubbul and embarks on an adventure that will carry him across the galaxy. He meets many people along the way and is exposed to a wide variety of ways of life, most notably the ways of the cult-like Free Trader community and those of the Hegemonic Guard of Earth and its surrounding planets.

When he is finally reunited with his birth family on Earth, he discovers that he is the principal heir to a huge fortune and a corporate empire. He soon finds, however, that personal liberty does not necessarily follow wealth and power. Thorby becomes overwhelmed by the responsibility and loss of privacy that result from the extremity of his newfound wealth, and quickly discovers that it will be impossible for him to return to his previous life as a common soldier in the hegemonic guard.

When he discovers that his family enterprise is involved in the slave trade, it becomes painfully clear to Thorby that he cannot morally justify avoiding his new power and responsibility. He begins the long, difficult legal process of taking control of the corporate entity (which is legally his) out of the hands of those who have been running the company during his long absence (and are hesitant to hand over their power).

After Thorby has finally obtained control of his familial estate, Rudbek, he embarks on a lifelong mission to eliminate slavery (as his foster father Baslim had done). Thorby enters this mission with the knowledge that it will likely cost him his life and that he cannot expect slavery to be eliminated in his lifetime.