Given that The Navigator's Children: The Last King of Osten Ard - Book 4 and it's predecessor, Into the Narrowdark were originally intended to be one single volume, it should come as no surprise that the third book in the series left a lot of storylines up in the air. For one, not only is the entire royal family scattered to the wind, pretty much every one of them thinks the others are dead or lost forever. King Simon is believed to be dead after fighting Unver, the Shane of the Thrivings. Queen Miriamele is thought to be dead by the hand of bandits. Prince Morgan has been lost and separated from his family since the first book and even young Princess Lillia is now lost in the bowels underneath Hayhold Castle.
To make matters worse, it seems that Pasevalles' plans are coming to fruition. Not only does he believe he's killed off the royal family, but he has used his position to claim the throne and is in the process of consolidating his power. Unfortunately for him (and fortunately for our heroes), it seems the High Throne isn't so easily wrested from Simon and Miri's legacy and there are uprisings that Pasevalles has to deal with before he can even begin to feel safe in his presumed position.
What Pasevalles doesn't realize is that one such uprising is orchestrated by "The Duchess," who is actually Miriamele acting in hiding. While those close to her know that she is alive, she is keeping that detail hidden until the timing is right to uproot Pasevalles and reveal him to be the traitor he is.
Meanwhile, Simon, still recovering from his fight with Unver, soon finds Lillia, but it seems that she isn't quite in her right mind. When a voice starts speaking through his granddaughter, he has to make some quick decisions, especially when that voice claims to be someone from his past whom he never thought he would speak to again. The question is, of course, is this voice who they claim to be and even if they are, can he truly trust them? What strange hands are guiding Simon and where will they lead him and his only living relative (at least as far as he knows)?
As for Simon and Miri's other grandchild, Prince Morgan has been lost in the Aldheorte Forest since he was separated from his men during the events of The Witchwood Crown. In that time, he has found himself in all kinds of strange situations. At first, he had to learn to survive on his own, but he did eventually stumble upon the Sithi and come under the care of Tanahaya, the Sithi who was sent to the Hayhold with an urgent message but was injured before meeting with the throne. When the Norns attacked the Sithi and displaced them, Morgan found himself once again changing hands, this time under the guard of Nezeru, a half-Norn Queen's Talon who has started having doubts about her lot in life. When Nezeru breaks from her troupe and abandons her position, she drags Morgan along with her and the two of them hide in the surrounding forest from Nezeru's former masters.
While it's clear that there is something blooming between Morgan and Nezeru, there are many reasons the two will not be able to stay together, and while Morgan is ready to admit his growing feelings, Nezeru has a lot of other feelings to work out about her own place in the world before she will even start to consider Morgan's place in it.
As the story of The Navigator's Children picks up pace, it becomes clear that most of the pieces are heading towards Narrowdark Valley, a place deep in Aldheorte forest. It becomes clear that Queen Utuk'ku's goal wasn't really to take back the Hayholt, but is actually aimed at this unusual part of the woods. It isn't far into this book before a massive battle erupts between the Norns, Sithi and what humans are present for the conflict, and that battle accounts for about half of the book itself. There are a lot of moving pieces during this part of the novel and it switches perspective often in order to keep all of the various threads in play, but Williams does an excellent job of keeping it all together and what results is a well-orchestrated and well-executed sequence of events worthy of this series' culmination.
Of course, that's really only half of The Navigator's Children, and the first half at that. What follows is a lot of cleaning up as the dust of that confrontation with Queen Utuk'ku settles. Revelations and family connections abound in the final stretch of The Last King of Osten Ard, as well as decisions about how the various surviving people will move forward.
The Navigator's Children: The Last King of Osten Ard - Book 4 is a fitting conclusion to this story and it not only expertly wraps up dozens of plots and subplots, it concludes mysteries whose seeds were started in the original Memory, Sorrow, and Thorn series. While this could easily be William's last foray into the world of Osten Ard (and it would be a good conclusion, if so), there are just enough openings created in these pages to give him another stint in this world. Either way, The Last King of Osten Ard has been a solid series that even those that haven't read of Simon and Miri's young adventures can pick up without having any problems.