The King in Darkness - Father Adam, #1

Adam Godwinson, former priest, isn't sure what he believes in anymore. These days he deals in used books at a small store in Ottawa. But an old text, written in an unfamiliar language, is about to change that forever. Adam now finds himself the target of a powerful conspiracy. These shadowy figures, wielding abilities he can't understand, want to cleanse society of its sins - even if that means destroying it.
Adam will have to figure out what he believes in to have a chance to save himself and the rest of the world.