The Fallen - The Fractured Series, #1

After the Demonic War, a battle which devastated the mortal realm, hunter cells were established across the globe to serve and protect every living soul. Maddison Wood is part of an alpha cell in the north of England. But Maddison has a new role now; her responsibilities as Watcher. She belongs to a legion of warriors assigned to serve the Fallen; guardian angels afforded the privilege of residing on Earth.
When Maddison is drawn to the city by an event which resonates hundreds of miles away, she is thrown into the path of a newly fallen angel. But Obadiah is no ordinary angel. He is a Prime, and his presence symbolizes a new threat. There is a war coming, and Maddison must form an alliance if she has any hope of winning this first battle. After all, the Fractured are a formidable enemy; a group of lost souls - powerful creatures of darkness who crave to destroy those who belong to the light.