Some secrets last a lifetime. When Becky and her mum move to the tiny village of Oakbridge, Mum is hoping for a new beginning. But when Becky discovers an old photo of her mum in hospital clutching a baby, twelve years before Becky was born, Becky becomes haunted by the thought that her mum is keeping something from her. Stifled by her mum's over-protectiveness and depressive moods, Becky feels more alone than ever. The only place she finds comfort is at the beautiful local Butterfly Garden with her new friend, the wild-spirited and impulsive Rosa May. But Becky can't shake off the unanswered questions. Why can't she swim? Where is her dad? Who is the baby in the photo? And why is her mum lying to her? As the two girls spend more time together however, Rosa May's unpredictable temper and possessive streak suggests that she is hiding something as well...and in the heat of the sun-drenched summer, it seems that Becky is the only one in the dark.