This is the second book but I don't think it actually matters much whether you read it before the first one. The stories are related but largely separate. 
 Here's my blurb: If you loved Roadside Picnic and House of Leaves, you will love this book. The author takes an interestingly kafkaesque approach with this story (we are all helpless before government bureaucracy and we can't change our fate). I enjoy the feeling of being drawn towards and inevitable and probably terrible conclusion. 
 Unfortunately that also describes my first marriage.