Leviathan — Thomas E. Sniegoski

Eighteen-year-old Aaron is on the run from the Powers that killed his foster parents and took his younger brother, Steven. With his dog, Gabriel, and Camael, a former Power, he is drawn north to a small town in Maine. Here Aaron, who still hasn't accepted his newfound heritage, finds comfort in the isolated, tight-knit community. But when Camael and Gabriel go missing, and their landlady suddenly attacks Aaron, he is forced to learn more about the War in Heaven and the many Powers that are fighting for dominance...of humankind.