This chapter is encompassed by a murky shroud of dread. What you don't know can hurt you and there is far too much which is unknown.
There was an abundance of trauma and benign neglect in Micco's young life brightened only by Billie and his friendship with Chase. It's understandable how he drifts back to the fondest memories of his childhood. Children tend to be resilient, but eight years of therapy indicate the depth of Micco's damage. He never had the unconditional love and understanding he needed from these strangers called family and it simply became part of the ongoing rush of tragedy he still suffers from.
I understand his desire to investigate Sam's house himself and Chase will as well, but no one else will. We remain as deeply in the dark as Micco over what is really going on. What would prompt Sam to put his house on the market? A desire or need to get away obviously, but from what?
I'm afraid characters named Billie bring up too many images of females; Billie Burke, Billie Piper, and Billie Holliday to name a few.