Jo Walton, writing at the height of her powers, has solved the second-book problem, or at least this one instance of the problem. The Philosopher Kings is in fact the middle book of a trilogy, but it is so much its own thing that although it has the advantages of a sequel—less time setting up the action, less need to clue readers in on how the world works—it strives relentlessly for its own excellence, and feels not at all like a bridge between first and third books. (Spoilers for the first book necessarily follow, as do some for the second.)
The Just City asked what would happen if people tried to put Plato’s Republic into practice, with a little help from the Olympian gods and goddesses. It was Athene’s experiment, and Apollo joined in because he wanted to learn what it was like to be incarnate, to see if there were things that he could only know from having experienced a full mortal life from beginning to end. The Philosopher Kings begins twenty years after the final scenes of The Just City, when Sokrates had demonstrated that the Workers, robots on which the city relied for manual labor, were sentient, Athena had departed in a huff taking all but two of the Workers with her, and some 150 citizens had stolen a ship and left the island under the leadership of Kebes, a child of the city who had never forgotten his Christian origins.
Twenty years later, the Platonists have splintered into five different groups, each with their own city and their own approach to creating the good life, as described in the Republic. Life is harder without the Workers to take care of most physical needs, although the two who remained (Crocus and Sixty-One) are valued citizens across the whole island of Kallisti, esteemed for both their physical capacities and their unusual cast of mind. Generational differences are starting to appear, as the Children who were originally acquired by the Masters have grown into adulthood and begun having children of their own, known collectively as the Young Ones. Education according to Plato’s precepts also includes training for war, and as the Young Ones grow into early adulthood some of them are keen to put their valor to more than theoretical testing, and to right what they perceive as a wrong done to the new cities; namely, that the original Just City kept all of the art that Athene and the Masters had liberated via time travel. Art raids have evolved into part of life on Kallisti, not unlike the steady warfare among Greek city-states in historical time.
Simmea, one of the narrators of The Just City, dies in an art raid in the very first chapter of The Philosopher Kings. Apollo narrates that chapter, and only in the moment of her death do readers learn that Simmea and Apollo (in his mortal guise as Pythaeus) have been married for two decades, have a daughter together, and are as happily conversing all those years later as they did when they still debated with Sokrates. An arrow brings all of that to an end, and grief undoes Apollo.
Walton shows the rippling effects of Simmea’s death through Apollo’s chapters, but even more through the parts of the novel narrated by Arete (Greek for “Excellence”), daughter of the union of Simmea and Apollo. Maia also returns as a narrator, now the voice of experience and an outsider to the family dynamic between Apollo and Arete. When none of the cities on Kallisti admits to harboring the art taken in the raid that killed Simmea, the theory grows that Kebes and his lost 150 may be responsible. Apollo wants to believe the theory because he and Kebes hated each other, not least because of rivalry over Simmea. Apollo proposes using the cities’ largest ship, the Excellence, to seek Kebes and extract vengeance. Cooler heads prevail, and the voyage of vengeance becomes one of discovery, planned to be safe enough to bring along people as young as Arete and as old as the venerable master Ficino, rescued from Renaissance Italy and now age ninety-nine.
The bulk of The Philosopher Kings follows the voyage around the Aegean. The sailors do not encounter the kinds of monsters that Odysseus found on the same seas, but what they do find is no less surprising. They see signs of religion that pre-dates worship of the Olympians; they see how precarious human settlement was, even in the friendly climate of the Aegean islands. Arete and her brothers are children of a god; the way to Olympus is in principle open to them, and they experience what that heroic inheritance means. The expedition also finds out what happened to Kebes and the others who left the Just City. They had not followed the Platonists’ ethos of non-interference in the settlements they found, forcing the people from Kallisti to radically revise their estimation of the world around them. Kebes also returned to his childhood Christianity, reconciling it with both the existence of the Olympians and the fact that the birth of the historical Jesus (who is called “Yayzus” in the text, which I found myself reading as “Yay Zeus”) is many centuries in the future. The climax of the book comes with a heart-pounding confrontation between Apollo and Kebes. As the ripples of Simmea’s death led to the voyage, so do the echoes of this confrontation suggest a solution to the troubles back on Kallisti.
The ending is both startling and makes perfect sense, completes the story and makes sure that the third book, Necessity, will stand as separately from The Philosopher Kings as that book did from The Just City. The ending is a deus ex machina, but then this is a Greek story, isn’t it?