Finished
Broken Prince by Glynn Stewart - House Adamant 5 (though it's more Adamant part 2, volume 1) and it met my high expectations - I got the audiobook as the narrator changed (sadly I didn't like the narrator for books 1-4 as I would have loved to listen to those too) and will be my next listen after I finish the last Underdog novel. My Goodreads review:
The original Adamant series featuring Lorraine, Val et co ended in book four in a definite manner though of course leaving the matter of FBIT and the wormhole for future installments and the author chose to start the second part with Nikola and Bonnie as main characters - while introduced before, Nikola has been mostly seen through the eyes of Lorraine especially in their powerful throne room confrontation, when he backed down from his intention of claiming the throne by right of conquest, though ultimately it was Lorraine and the three Valkyries (ultra powerful sentient battleships Lorraine "liberated" from distant Earth, managed to convince them to help defeat the Black Regent, and then succeeded to keep hold of due to the interstellar treaties guranteeing personhood to such, though with important concessions regarding their capabilities), who beat the Black Regent, and submit to the traditional Pentarch election process which he knew he would lose to his sister...
Now haunted by the losses in the civil war, Nikola is given the most important mission by his sister, namely coordinate the search for the unknown wormhole whose presumed presence in or near Adamant space led to all the bloodshed - at least if what the late regent, Benjamin Adamant, claimed in his posthumous "defeat" message to his vanquishers was indeed the truth and not a justification for his murderous actions. But Nikola is also an infantry officer who led the resistance against his uncle for a year, so the survivors of the elite corps he led clamor for him to command them - to combine the secret mission with his new role, Nikola - with Bonnie of the three Valkyries as flagship - has to go on a tour of the outer systems, ostensibly to show the flag, but in reality to chase any FBIT remnants and coordinate the search.
Tolkien, the closest to the powerful Richelieu Directorate - and whose invasion decades ago led to Benjamin's lifelong secret resentment against his sister and eventually to the coup in which he murdered her and a couple of her children but failed to get Lorraine and Nikola - has recently been suffering a surfeit of pirate attacks nearby, and in thwarting one such, the just arrived Nikola meets an old acquaintance of Bonnie and discovers disturbing news; despite its defeat, the Directorate seems to be behind the surge in piracy and is massively building up a force in the closest system to Adamant space. And so it goes, with lots of cool stuff - despite being a general, Nikola trades on his status as prince - first pentarch - to be in the thick of the action as he is the only one who can fully commit the Adamant kingdom's word for this and that.
While starting slow - getting acquainted with Nikola and his inner demons, learning more about Bonnie etc the novel moves well, and when the action starts, it never stops until the perfect tbc point
Lots of cool touches - the D'Artagnan class of Richelieu warships, the battle cruiser Porthos, the West African based cultures and traditions of various planets around etc
Overall, the author moves smoothly to a new pair of main characters - and lots of interesting secondary ones, some old but mostly new - and the 6th series book is another huge asap as we suspect that much more is at stake than a border squabble.