Prolific novelist and Tacoma resident Robin Hobb wraps up her Rain Wilds tetralogy with Blood of Dragons (available in hardcover and e-book editions) — which should not be confused with the role-playing game based on George R. R. Martin’s work, despite his jacket blurb: “Robin Hobb’s books are diamonds in a sea of zircons.”

Because Hobb has visited the world in which the Rain Wilds series is set before, there’s a detailed expansiveness to her landscape that you don’t always come across in fantasy novels. But where Martin’s genius was employing the preoccupations of teenage boys (a fantasy staple) to vivify the geopolitics of the Hundred Year’s War, Hobb is more of an existentialist, and the Rain Wilds a kind of proving ground for the task of becoming. Illusions are cast aside, or they swallow up lives. Choices define characters. Society impinges.

The series is richly — even baroquely — layered with resonant relationships that forego strict analogy; at times, the dragons are like impatient parents, all too mindful of their short-lived human charges’ ignorance of deep history, while at others, the roles are reversed, the dragons all potential, while their human minders try simply to keep them from injuring themselves before they’ve grown into adulthood. In Hobb’s hands, the Freudian id gets an interior monologue — the juvenile dragons’ comical, inept lunging after desires is what instinct looks like training the body.

The series begins with Alise, the sheltered, “trader”-class daughter who has appointed herself a dragon scholar, taking time out from her recent marriage to go on a research expedition. A clutch of young dragons are being fostered by Rain Wilds residents, and it’s too much to pass up — even though people in that region display odd genetic mutations, to the extent that severely malformed newborns are exposed and left to die. That was the barely avoided fate of Thymara, a young, scaly, clawed girl who signs up to be a dragon-minder.

By the time Blood of Dragons opens, the motley crew of dragons and their equally motley dragon-sitters have come a long way in their quest to (re)discover who they are, but just as they’re poised to fully explore an ancestral home, antipathy and envy are rising against them. They’re too valuable dissected, for one thing, too dangerous nearly grown, for another. As the book opens, the dragon matriarch, Tintaglia, has been wounded by humans. Though Hobb’s style is not immune to ersatz “fantasie speeche” (Tintaglia’s consort is called Icefyre), she’s more than capable of crisp, grounded storytelling:

The festering wound under her left wing made it hard to find a comfortable position. If she stretched out, the hot swollen place pulled, and if she curled up, she felt the jabbing of the buried arrow. The pain spread out in her wing now if she opened it, as if some thistly plant were sending out runners inside her, prickling her with thorns as it spread.

There’s a lot of coming home to roost, for humans as well as dragons, here. Alise’s estranged husband is hunting her down. Sedric, out and proud with a bear-ish partner, has to face his closeted past. The relationships between dragons and humans become even more intertwined, though the jockeying for superiority hasn’t let up. Thymara is still hounded by partly-unwanted suitors, and quarreling with herself about commitment and autonomy. As she has throughout the series, Hobb presses hot buttons: genetic mutations can sound a lot like “special needs,” the plight of a liveship can sound like involuntary servitude or slavery — but to Hobb’s credit, it’s also the ways in which they don’t sound like analogues that help you see things in new lights.

In summary form, this might seem heady stuff, and I imagine fans love talking it out, but Hobb doesn’t short you on plot, either. Leading characters may be a little too prone to extended interior monologue, but there’s also a good deal of excitement and intrigue as the outcasts struggle upriver, in addition to a creepy, vampiric subplot involving an imprisoned dragon singer. For good measure, there’s something called “memory walking” which is a bit like being an opium-and-historical-research addict. There’s nothing pat that is produced, with Hobb — she seems incapable of it. Everything comes with fascinating facets, revealed in their own time.