The premise is Kendro, King of the Aonise, is gathering the population of the planet Lethao in four crowded starships. Their sun is about to go nova in a suitably Kryptonian fashion and they must find the planet Earth in order to survive. Unfortunately, for Kendro, his wife is pregnant and if this fact is discovered then both would be targets during this time of unrest. Kendro's closest relative and strongest supporter is caught in a scandal which would expose his sexuality to their homphobic society. Finally, an ancient member of their race has been found in stasis and brings news of a threat very close to home. That's in addition to the Zefron, a race which seems to want nothing more than to extinguish the Aonise people.
Kendro is a remarkably progressive leader for an absolute monarch and serves as our chief POV character alongside his brother Octav and commoner Doctor Katya Brie. Kendro is a dynamic personality who is able to change Aonise society seemingly on a whim but who is stretched thin due to all of the balls he's juggling. Octav, by contrast, is far more conservative and has shot himself in the foot with these attitudes since they've trapped him in a one-sided marriage and deprived him of a relationship with his subordinate Chace. Chase, notably, is also a member of the outcasts who sit at the bottom of Aonise society.
Parallels to the original Battlestar Galactica exist but by the end of the book, I considered The Secret King to be its own thing. Indeed, I tend to think of this more as fantasy IN SPACE versus traditional space opera. The Aonise possess psychic abilities which function a great deal like magic and affect their society on every level. The inter-house politics are entertaining and take an interesting turn once we discover the origins of the Aonise ruling class.
Dawn Chapman has an excellent feel for world-building and we get a real sense of how the Aonise have functioned for the past few millennium. They're not a race of perfect people with numerous flaws to their society. For example, they have a caste system of unbound who have been grudgingly included in the Aonise arks and have numbers to demand the rights they've always wanted. Also, the fact the society hasn't advanced enough to treat homosexuality as a matter between consenting adults is depressing.
Romance plays a big role in the book but in a idealized hooey-gooey manner. The love interests fight, break up, and struggle over events. One thing I liked about the Octav and Chace romance is there's some decidedly unsympathetic elements about the former. Octav may love Chace but it's clear the latter loves him more. It's not a story of love conquering all and Octav is almost embarrassed to the lengths his brother goes to see he's happy. We also are never quite sure if Octav's wife is with him for love or the power which comes to being married into the royal family. I also was a big fan of Doctor Katya Brie and her husband who suffer a major break in their relationship over the fact the former is willing to sacrifice their unborn child's life to save the royal family's heir.
There's plenty of action throughout the book and I was especially fond of the space battles we get as each of the arcs is put into danger across the book's story. The fact whole sections of the population are put in danger in each engagement is a source of real tension and Dawn Chapman doesn't let her heroes get through the book unscathed. I liked the inclusion of psychic powers as part of the Aonise physiology as it allows the battles to have a mystical element that spices them up even more.
The book suffers a bit for the fact the protagonists are all good and the antagonists are completely evil. We never really find out why the Zefron are so determined to wipe out the Aonise place and so they remain an implacable bunch of Daleks who have to be destroyed rather than a more nuanced three-dimensional set of antagonists. Dalamarr, the mysterious Big Bad of the story, wants nothing more than to rule the Aonise and has only one virtue that he's willing to hold off on his power grab until Kendro has successfully evacuated the planet.
The book is a bit small for how much the story covers, ironically. It feels very much like a 13-episode television series condensed into only a few hundred pages. [Note: This turns out to have been a remarkably apt observation since I've been informed the series started out as a television show pitch.] I think the book could have easily been expanded another fifty to a hundred pages without watering down the story. As such, there's a lot of rushing around before the book reaches its climax.
Despite this flaw, I really recommend this book. It's entertaining from start to finish and manages to tell an epic story in a medium-sized 307 page volume.