Perdition Street by Leona O'Neill

Murdered spirits find Atlas Bishop wherever he is. By day, he works the streets of Dublin as a Private Detective plagued with anxiety and anger issues, living with his dead mother. By night, he works on behalf of the “Sacred”—angels, saints, and God Himself—binding murdered souls to those who stole their lives so Hell can claim its dues. But an ancient pact between Heaven and Hell implodes when Hell’s representative on Earth decides he wants to swell their ranks and take over the world, using dark magic to turn innocents into murderers on an epic scale. Atlas must save Dublin first and then the world, all while trying to bind lost souls, keep Heaven in business, track down his killer father, pine for his married ex-lover, escape various murderous scum…and avoid Satan’s manicured talons.