Gone Girl: A Wedding Anniversary,a Missing Wife and a Bitter Husband

I am reading Gone Girl a novel  by Gillian Flynn.  This is the Book Club's pick for June. The setting is Missouri.  It is the day of Amy's and Nick's fifth wedding anniversary and Amy is missing. The story is told from Nick's point of view as  the search for Amy progresses and also from Amy's point of view, before she goes missing. We get Amy's point of view in a diary format.  Frankly the husband is very suspicious.  He is an unhappy man,from a dysfunctional family, who tells these little half truths to the police. Amy is a strange woman with too-perfect New York parents who are writers of a story in which the protagonist is also named Amy. She has these treasure hunts for her husband on every anniversary.  He never is able to figure out all the clues yet she keeps writing them anyway.

I am loving the story so far because there is a lot to keep my attention. Why does Nick have a disposable phone? Why did Amy buy a gun? Where will these fifth anniversary clues ultimately lead Nick?  The clues are little love notes that suggest that she was happy with Nick so who was Amy afraid of really?  I am on page 139 and I am enjoying this.