The Sword that Binds (Book of Worlds 1)

Born in a kingdom where magic was all but forgotten, Sarena Garland has come of age to inherit Heartseeker, the ancient, magical blade of Garland Keep. However, her joy is short-lived when Heartseeker awakens and strikes down the prince, forcing her to flee for her life into the forbidding Godwoods. There she discovers that not only is Heartseeker magical, but there is an ancient soul that resides within it - Tyrus. As she struggles to survive, Tyrus’ magical bond threatens to consume her. When a long forgotten god offers them the chance to escape their fate, Sarena and Tyrus have no choice but to agree.

After all, how hard could it be to find a book in a library?