Shadowrun: Stolen Souls advances elements of the Sixth World’s metaplot while providing some useful resources and advice. Do you need this book? Well, if you want to understand the mystery of the Head Cases, yes. If you want to run a game set in 2070s New York, yes. But for me, it is the discussion of extraction tricks and tactics that makes this book immensely useful as it is one of my favorite types of mission to use as a GM. But your campaign is your campaign, so see if this will help and purchase it if the answer is yes.