Good Day Sunshine

"For Jackie Pierce, everything changed the summer of 1979, when she spent three months of infinite freedom at her bohemian uncle's sprawling estate ... Jackie and her cousin Willa fell into a fast friendship, testing their limits along the rocky beach ... until the summer abruptly ended in tragedy, and Willa silently slipped away into the night. Twenty years later, Jackie unexpectedly inherits The Sandcastle and ... when a piece of the past ... sparks new questions about Willa's disappearance, Jackie must discover if the dark secret she's kept ever since is even the truth at all"--