Dark Days : The Casting!
I'm not going to go into the details and spoil it for everyone but I recommend you read this book. I think its a game changer and I can't remember reading a book this good for a while, obviously start with The Forge but this book will be an important book for the DC Universe.
There are 2 variant covers (B and C) by Kubert and Romita that are worth picking up as well especially as they're cover price.
I've never really been a DC reader always been a Marvel guy but DC are kicking Marvels arse with storytelling at the moment !!