Vicious Grace (The Black Sun's Daughter, #3) by M.L.N. Hanover
Blurb from Goodreads:
For the first time in forever, Jayné Heller’s life is making sense. Even if she routinely risks her life to destroy demonic parasites that prey on mortals, she now has friends, colleagues, a trusted lover, and newfound confidence in the mission she inherited from her wealthy, mysterious uncle. Her next job might just rob her of all of them. At Grace Memorial Hospital in Chicago, something is stirring. Patients are going AWOL and research subjects share the same sinister dreams. Half a century ago, something was buried under Grace in a terrible ritual, and it’s straining to be free. Jayné is primed to take on whatever’s about to be let loose. Yet the greatest danger now may not be the huge, unseen force lurking below, but the evil that has been hiding in plain sight all along—taking her ever closer to losing her body, her mind, and her soul. . . .
An almost unexpected ending aside from the nagging thought in your mind that was finally calmed by the revelation. The convolutions of motivations and the horrific truths revealed were handled beautifully. Overall the book is a wonderful continuation of Jayne's tale.