How does one store memories? How does one perceive reality? Joe Hill expands on this idea that he teased with in the first volume and takes it up a notch. A key to open head and stuff books in it, extract information - fear, memories and stuff them in a glass jar. It's such a unique idea! Its even more fascinating to see how Joe Hill subtly explains the working of the key and its functions which is an allegory to working of the mind. 
 Every supporting character meets with a tragic end, the enemy growing stronger and closer to the family integrating into their lives to the point that they trust the enemy implicitly. The kids are lovable characters and we know more about them in this volume. 
 The art is amazing. Its bolder and vivid when we look inside someone's head and muted in real world. The enemy is a well rounded gay character with a back story. 
 This volume is better than the first as the story telling is slowed down considerably and the characters are given their own space to explore. It works well and when the arc culminates, it all comes together. 
 After reading NOS4A2, I really didn't expect Joe Hill to be this awesome.