"Library of Souls" is the third and final novel in the "Miss Peregrine's Peculiar Children" series by Ransom Riggs. The story picks up where the second novel left off, with Jacob Portman and his peculiar friends Emma and Addison on a mission to rescue their beloved headmistress, Miss Peregrine, who has been kidnapped by the evil wights. Their journey takes them to the Library of Souls, a mysterious place where peculiar souls are stored in jars. Along the way, they encounter new allies and enemies, and uncover dark secrets about the peculiar world. The novel is filled with suspense, action, and fantastical imagery, and concludes with a thrilling and satisfying climax. "Library of Souls" has been praised for its creative world-building, its memorable characters, and its ability to keep readers on the edge of their seats.