Prison of Night
1977

Plot
Dumarest begins the story still on Zakym, apparently a few months after the end of Book 16, Haven of Darkness.  He has been granted Gydapen’s estate but is suffering some mental instability from what he later learns is a side effect of the same radiations that cause delusia: they are preventing the dominant half of the Affinity Twin in his brain which should have dissolved after Chagney’s death from doing so.  While he suffers increasingly disturbing bouts of delusia involving dead lovers and foes, the mercenary group hired by Gydapen to assist in taking over Zakym seeks a way to salvage their investment.  The mercenaries present a false heir whose background story is plausible enough to convince the council his claim should be heard (since most of them don’t like the fact that Dumarest, an off-worlder, now holds a traditionally inherited rank).

While the legal proceedings drag on, the false heir picks up where Gydapen left off, but with an army of professional mercenaries and the advice of Cyber Ardoch (who really only wants Dumarest, but is more than willing to bring another world under Cyclan influence as a fringe benefit).  Warned of the extent of the plot by Kars Gartok, a rival mercenary, Dumarest leads a futile resistance, and the only reason it’s even marginally successful is that Ardoch is giving the mercenaries advice designed primarily to keep Dumarest alive.  Dumarest attempts to use the deadly nocturnal life forms he first encountered in Book 16 (and which he believes are connected with the Sungari) to his advantage by tearing down the enemy barracks at night, but Ardoch has anticipated this move and the plan fails.  In the process, however, something clicks.

Dumarest realizes he knows far more about the Sungari than even his considerable intuition can account for, and he contacts them directly (seemingly breaking The Pact in the process).  The Sungari are indeed an alien life form that colonized Zakym before humans arrived.  “They” are actually an “it” – a giant communal life-form consisting of the combined minds of all its members, of which the variety is staggering (including the nocturnal killers).  The Sungari were only able to communicate with the early humans because some of the original settlers were telepathic.  Fortunately, the surviving Affinity Twin in Dumarest’s brain has provided a channel through which they can communicate.  They are curious as to why humans broke contact, and about what’s happened in the intervening centuries.  Dumarest gives them the lowdown, putting emphasis on current events, offers a new Pact, and they quickly destroy the entire mercenary force. 

Upon returning to Lavinia’s estate, Dumarest learns that Ardoch has survived and kidnapped Lavinia, who by now is pregnant with Dumarest’s child.  Knowing he must leave Zakym or go insane from the continued presence of the Affinity Twin in his mind, he convinces both Lavinia and Ardoch that he doesn’t really care if she lives or dies.  This not only causes Lavinia to fall rather quickly out of love with Dumarest, but also saves her life.  While Ardoch is distracted by this apparent flaw in his logic, the Sungari fry him.  Dumarest encourages Roland to pursue his romantic interest in Lavinia (and presumably to provide an adequate father figure for Dumarest’s child), and resumes his search for Earth.  Gartok, who has become friends with Dumarest during the resistance fighting, stays on Zakym to assist with the rebuilding effort.

Clues of Earth
None

The Cyclan
Dumarest spoils the Cyclan’s chances of bringing Zakym under their influence (although that goal was merely an offshoot of their attempt to capture him) and brings about the death of Cyber Ardoch.

The Journey
Dumarest begins Book 17, Prison of Night, on Zakym and the book closes with him still there, awaiting the departure of a ship to Izhma.

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