The Shadow Queen is the latest installment of the Black Jewels series, either Book 6 or Book 7 depending on whether you count only the novels or include the novella/short story collection. It is a series in the loosest sense; the books are set in the same world and there is some overlap of characters and timeline, but some are designed to stand alone.
The Shadow Queen is both a sequel of sorts to the original Black Jewels trilogy (Daughter of the Blood, Heir to the Shadows, Queen of the Darkness), in that it picks up with a new set of characters right after the cataclysmic world-changing end of the trilogy, and also a sequel to the only true stand-alone novel, The Invisible Ring, because it follows the descendents of the characters in that story. This book introduces Theran Grayhaven, the last descendent of the Gray Lady—the last good Queen in his homeland of Dena Nehele—who needs to find a Queen who lives by the old ways to rule his people and help bring his land back to life. He is sent a Queen named Cassidy, a woman who isn’t sure she’s up to the job and needs the validation of being useful as much as Dena Nehele needs a good Queen. In order to accomplish the job she was sent to do, she must learn to trust herself—and convince the embittered, angry members of her new Court to serve her willingly. If she can’t, Dena Nehele will fall.
Elena Nola is the imperial movie critic and the colder half of the Ladies of Ice and Fire.