Mercy Sparx: Year One (Mercy Sparx: Year One #2)

We continue to learn more about Mercy's childhood growing up in Sheol, tossed about from Mother to institutional foster care to... Ancient Sumerian biker guardian? Just who is Karduk, and how did he become Mercy's closest thing to a father growing up, and how does the angel Hillevi tie into not only his past, but Mercy's parents too?