The Library of Broken Worlds — Alaya Dawn Johnson

A girl matches wits with a war god in this kaleidoscopic, thought-provoking tale of oppression and the cost of peace, where stories hide within other stories, and narrative has the power to heal -- or to burn everything in its path -- from World Fantasy Awardâ€"winning author Alaya Dawn Johnson.
A girl and a god, alone in communion ...

In the winding underground tunnels of the Library, the great peacekeeper of the three systems, a heinous secret lies buried -- and Freida is the only one who can uncover it. As the daughter of a Library god, Freida has spent her whole life exploring the Library's ever-changing tunnels and communing with the gods. Her unparalleled access makes her unique -- and dangerous.

When Freida meets Joshua, a Tierran boy desperate to save his people, and Nergui, a Disciple from a persecuted religious minority, Freida is compelled to help them. But in order to do so, she will have to venture deeper into the Library than she has ever known. There she will discover the atrocities of the past, the truth of her origins, and the impossibility of her future.

With the world at the brink of war, Freida embarks on a journey to fulfill her destiny, one that pits her against an ancient war god. Her mission is straightforward: Destroy the god before he can rain hellfire upon thousands of innocent lives -- if he doesn't destroy her first.