In the Blake's 7 series, Avon's first name is usually given as Kerr, with a double r. However, in the novel it is consistently spelled Ker with a single r. This is explained as a short form of his full name Kerguelen, said to mean desolation. The latter is either a misunderstanding or poetic license on Darrow's part, probably based on the Kerguelen Islands in the southern Indian Ocean, which are sometimes known as "Desolation Islands." The name Kerguelen is, however, not a direct translation of "desolation," but a reference to the discoverer of the archipelago. Since the novel consistently uses Ker, this form is preferred for use in this article.
The story begins approximately 26 or 27 Earth years before the events of Blake's 7 proper, when Rogue Avon, a former professional assassin defected from the Federation death squads, on the run from his former employers, briefly meets a young woman called Rowena and fathers a child, the future Ker Avon, before continuing his attempts to evade his pursuers and reach Earth.
The first part of the novel follows the further adventures of Rogue Avon as he travels from Phax, a fictitious moon of Uranus, through the Clouds of Magellan to Earth, where he is eventually killed by his half brother Axel Reiss, who has remained loyal to the Federation. The second part of the novel details Rowena's endeavours to raise her son Kerguelen and avenge his father; however, she fails in the latter and is killed on Reiss' orders. The third part portrays Reiss' attempts to mould the education of the young Ker Avon in order to use him in his schemes to achieve more power in the Federation hierarchy.
In the fourth and final part of the novel, these plans misfire when Ker Avon, whose intelligence and survival skills have been honed in the challenging environment of Federation intrigue and double cross, turns the tables on Reiss and kills him, partly to avenge his father and partly as an element in his scheme to defraud the Federation banking system and abscond to a safe haven outside the Federation's sphere of influence. However, in the course of his final duel with Reiss, Avon sustains injuries that prevent him from avoiding capture. Avon is sentenced to be deported to the prison colony of Cygnus Alpha, and the novel ends as Avon boards the Federation prison ship London, seconds before the beginning of the first season episode Space Fall in which Avon first meets Blake.
The novel is strikingly true to the original Blake's 7 universe in its portrayal of moral ambiguity and corruption. Some characters, such as the enigmatic Prospector, seem to be more successful in living up to a standard of moral integrity than others, but none are incorruptible; their moral code is pragmatic at best. Indeed, treachery seems to be the rule in the Federation universe, most people being all too ready to abandon and betray previous alliances and commitments to further their own ends. Avon, his father Rogue, and Axel Reiss are all approached by various parties proposing that they betray or even kill former allies. The whole Federation hierarchy is dominated by shifting power blocs manoeuvring for control. The devious, scheming Vasht in particular is notably reminiscent of Servalan in the series, even to details in her personal demeanour.
Some departures from canonicity occur in terms of plot. Besides Ker Avon himself, a few other characters such as Tynus and Anna Grant are shared with the series, and particularly in the case of Anna Grant there are significant departures from the character as portrayed in the series. In the novel, she is a drug addicted, sociopathic tool in the hands of Axel Reiss, quite different from the admittedly treacherous but strong willed and self-possessed Anna Grant as portrayed in the third season episode Rumours of Death. Similarly, the events leading up to Avon's capture in the novel disagree in many respects with Avon's relation of those same events to Del Grant in Countdown: in the series, Avon attributes his injuries to the man who was arranging for his getaway (a reasonable enough match for Maco in the novel); however, the duel with his uncle, a major event in the novel (and arguably in Avon's life), also takes place after he left Anna but is not mentioned at all in the series.
Other apparent departures from the canon are of a technical kind. In particular, the Federation universe in the novel seems to be largely contained within the boundaries of the solar system. Avon's conception and birth take place on a (fictional) moon of Uranus; Rogue Avon's laborious return to Earth involves hopping between various fictitious asteroids all firmly located between Saturn and Earth; and the intriguing "Clouds of Magellan", a clear reference to the Magellanic clouds, appear to be located in close Earth orbit. Likewise, Cygnus Alpha, most definitely located well beyond the solar system, is described as "newly acquired by the Federation", although, in the series episode Cygnus Alpha, Vargas in his talk with Blake makes it quite clear that prisoners have been sent there for generations. However, since similar mistakes in astronomical technicalities are routinely made in the original series, it is debatable whether this represents a departure from the series canon.
Given Darrow's background as a theatre actor, it is perhaps not surprising that the novel abounds in Shakespearean references and quotations, from the title itself—a quotation from Henry V—to Raher quoting Julius Caesar several times in his final conversation with Avon.