Another Barbara Hambly homerun. Her worldbuilding is peerless. She manages to create an entire setting, complete with societies, factions, civic rules, individual cities, monsters, realistic characters, and vibrant plots without bogging her readers down in the faux biblical/foundational myth nonsense of other fantasy authors who follow Tolkien's methods too slavishly--not realizing that Tolkien's worldbuilding is actually (to me, anyway) one of his lesser skills as an author.
On the contrary, Hambly leads her readers gently into her world, revealing its secrets and wonders in small doses, which has the dual effect of both allowing the reader to grasp the world's details more fully, and also causing the reader to want to learn more, thus enriching the mystery of the book's central plot.
But Hambly does this in every one of her fantasy novels. So what makes this one special? Here, she's developed a world in which wizards are not all-powerful men and women who hold the fate of their realms in their hands, but are rather shunned by the general populace and, indeed, even at constant risk of death, for killing a wizard here is not considered a crime. Wizards cannot marry, they cannot run a business, or really do anything a "normal" person could do because society believes that wizards might use their powers to unnaturally influence their spouses, business partners, customers, and so on. Wizards are, essentially, the lowest rung on civilization's ladder.
So our protagonist, Rhion, is not some Gandalfian superhero but a veritable pauper who makes his living selling love potions to people who sneak carefully to his apartment so that no one who knows them might see that they are consorting with a sorcerer. But selling one of these potions to the wrong person causes Rhion and his mentor, Jaldis (whose eyes and tongue were cut out when his royal patron was put on trial), to go on the run.
Hambly takes us on a tour of the Forty Civilized Realms, from the city of Felsplex to the Drowned Lands of Sligo (home to the Marshmen and the Gray Lady, leader of the Witches of the Moon, a rival order of wizards) before settling in Bragenmere, ruled by Dinar Prinagos, the Duke of Mere--who also happens to be the father of Tally, whom Rhion and Jaldis rescued from demonic grims in the Imber Hills. The Duke is kind to wizards, and provides Jaldis and his pupil with rooms and free access to his library. But all is not well, because Tally's brother-in-law, Esrex, is in league with the priests of the Veiled God, and somehow they have learned that Rhion has entered into an inappropriate relationship with the Duke's daughter.
There's also the rainbow abyss of the title, but this is more of a background plot point until the book's final chapters. We'll learn more about that in the second and final novel in the Sun-Cross series.
As usual, Hambly's books inspire me to take what she has built and turn it into a Dungeons & Dragons setting. Perhaps moreso than her other books, The Rainbow Abyss provides a unique setting opportunity, not just in the way that wizards are treated by the intensely religious Forty Civilized Realms, but also with her conception of a wizard's magical practice. I could easily write an entire RPG supplement based on this book alone. I think it's fair to say that Barbara Hambly is my favorite fantasy author of all time. What a talent!