The Sound at the Edge — Angela Day

Thane found the power of his Song in time to save his best friend Remi, but in so doing, burned it out. He's left part dragon, part human, and songless to start over again in Sanctum to train himself to control the monster that rages within. Remi comes along and discovers her mother is alive. Trapped in the Shaerealm and held captive, Remi's mother might have found a weapon that could change the balance of power in the realms forever. But Sanctum won't save her. It's up to Remi, Thane, and anyone else they can convince to come with them to break all the rules and bargain with the ancient ones to find a way across the void of space and escape to a world where all the laws of nature have changed. If they succeed they'll reunite a family. If they fail, they and anyone with them will die. And if they can't make the journey in the right way at the right time with the right people, the Weave itself may unravel and drag all their worlds into unmaking.