The Coming of Wisdom has all of Dave Duncan's usual light fantasy charm and personality, but less in the way of structure and plot. It's a solidly entertaining continuation of the storyline, but not much more, and the ending is weak.
Duncan most often writes about likeable everyman heroes in difficult spots; part of his appeal is his ability to bring readers along to ponder ethical and practical dilemmas. He accomplishes that ably in this book. Wallie, from a different world, struggles constantly to understand and work with local strictures and mores that seem impractical and even dangerous. He's been given divine proof that things are different here, and he'd better conform, but struggles to keep his own moral sense intact. Duncan does a nice job of making the struggle entertaining.
At the mid-point of the series, larger moral issues have faded into the background a ways. While Wallie struggled with slavery in the prior book, here it's an accepted fact. He owns his lover, and that's the way it is. To his credit, Duncan mostly pulls that off - Wallie seldom loses sight of the fact that it's not an equal relationship (with one uncomfortable exception). Other slaves don't come off as well, and there's one change of cast that not only highlights the issue of slavery, but suggests that Duncan simply changed his mind partway through the story, as he dumps a character who never did much but stand around and stare. There's a possibility it was an intentional plot support, but it comes off as clumsy and jolting. There are several minor inconsistencies in the world and environment that stick out as well. Gender continues to be out of balance, with a very male oriented story. At one point, Wallie determines that a young priestess 'deserves' a better life - as far as I can tell, only on the basis that pretty (and smart, but the emphasis seems to be on pretty). One woman has 'an old man's eyes' - seemingly because they're hard and cunning.
Duncan's strength has always been more in friendly style than intricate plot, but most of his stories can hold their own. In this book, however, after a time the plot seems to degenerate into a long chase scene. Go to city, have adventure, figure out part of the riddle, go to another city... While Duncan handles one of the key puzzles well, he fails to consider a host of possible explanations for others, and seems to forget one entirely. The goddess needs Wallie, and won't promise miracles, but does quite a lot of intervening. The approach holds up for a good while, but loses appeal toward the end. A parallel to Philip Jose Farmer's classic river series goes seemingly unacknowledged.
The more problematic issue, however, is the ending. As the end of the book approached, I wondered more and more intensely how Duncan would be able to pull off a finale in just 50 pages... 40.... 30... 10... The answer is, of course, that he doesn't. There's a little set piece to balance things a bit, but basically the book just stops, leaving the big action for book three. It's disappointing, and far from making me anxious for the conclusion of the trilogy, suggests that I know pretty well what's coming.
All in all, a decent read, and a modest continuation of the series, but not Duncans best, and not satisfying in itself.