City of Bones by Cassandra Clare

"City of Bones" follows Clary Fray, a seemingly ordinary teenager, who discovers her hidden heritage as a Shadowhunter, a human-angel hybrid tasked with protecting the world from demons. Her life is upended when her mother is attacked and kidnapped, thrusting her into a supernatural world she never knew existed. Clary joins forces with a group of Shadowhunters, Jace, Isabelle, and Alec, to rescue her mother and uncover the secrets of her past. The group battles demons and uncovers a plot by Valentine, Clary's father, to obtain the Mortal Cup, a powerful artifact, and cleanse the world of Downworlders. Clary must come to terms with her identity, her complicated relationships, and her role in the impending war. Ultimately, she embraces her destiny and prepares to confront the dark forces threatening to consume the world she thought she knew.