Alex Walker has always looked up to her perfect older sister. Maddie has succeeded in all the ways Alex has not: She escaped their hometown and seems to have put the memories of their unstable childhood behind her. But despite the different paths their lives have taken, the two sisters made a pact to spend one week together every summer. When Maddie suddenly cancels her annual trip home, Alex begins to worry. But when Maddie stops returning her calls altogether, Alex follows her sister's footsteps to the Hamptons where she meets the Blackwell family - the last people to have seen Maddie before she vanished into thin air. The Blackwells seem to have it all: wealth, beauty, and a beachside mansion on a private stretch of Hamptons real estate. It's a world unlike any Alex has ever known, but she quickly discovers that looks can be deceiving, and that a life of luxury always comes at a cost.