You and the Night - The Muse Chronicles, #3

How far would you go to protect the world of Art? Musician, Sylvia Baker, has been through a lot to find her place in the world of the Muses. She's always seen these mysterious beings as they Inspire artists, which led her to stay in a psychiatric hospital multiple times and question her own sanity. She's finally accepted the Muses and her connection to them, and she's fallen in love with her Muse, Vincent, as they create music together.
She even climbed Mount Olympus to save him. But while she was in the Village of the Gods, she managed to wake Ares, the God of War. Ares latches onto a conflict between the traditional and modern Muses, starting a war between them. As the war rages on, it threatens Sylvia, Vincent, and all the Muses she has come to love. But when she discovers she may be the key to ending the war, she has an impossible decision to make before Ares and his followers destroy everything. Fans of The Mortal Instruments and Daughter of Smoke and Bone will love the exciting conclusion to The Muse Chronicles trilogy.