It is part of Dickson's Childe Cycle series, in which mankind has reached the stars and divided into specialized splinter groups.

Themes from the rest of the cycle are echoed here, particularly the actions of key people, like Paul Formain, Cletus Grahame and Donal Graeme in the other novels, who can drastically affect history due to his ability to analyze and influence the behavior of others.

In the late 23rd century, humanity settled fifteen younger worlds around nine stars, including Earth's solar system.

Most notable of these are: the Exotics, philosophers, mystics and psychologists; the Friendlies, puritan faith-holders who supplement the meager production of their rocky worlds by hiring out as mercenaries; and the Dorsai, true professional soldiers, highly skilled and expertly trained.

Orphaned at a young age, and raised by a nihilist uncle, he cares little for others, with the possible exception of his younger sister, Eileen.

In a prelude to the main events of the novel, he and Eileen visit the Final Encyclopedia, a centuries-long project to try to collect and catalog all knowledge.

The dying director of the Encyclopedia wants him to stay on and succeed him, but an Exotic, Padma from the planet Mara, reads him as having no identity with others, no empathy, no soul.

On one side are the mercenary forces hired by the Exotics, led by the identical Dorsai twin brothers, Ian and Kensie Graeme.

Tam has manipulated the situation so that not only will the Friendlies lose, but their ability to hire out their soldiers will be crippled, possibly leading to the end of their viability as a culture.

He gives Tam a copy of a secret communication between Jamethon's superiors that appears to abandon hope of them winning, and leave them to be destroyed, and further to conceal this from the troops.

By rejecting what he saw as the Devil's Choice of surrendering to save his own life, Jamethon saw a way to end the conflict by sacrificing himself in a futile attempt to assassinate a vastly superior Dorsai officer.

As Padma explains to him, had Tam succeeded, not only would a necessary component of the human spirit have been lost, but the entire balance of power among the worlds would have been horribly upset.

Eventually, Padma manages to break through his shell, allowing Tam to grow into more of a human being, and take his place at the Final Encyclopedia.