1914: Anticipating a long summer of freedom at her friend's family estate in Cambridge, Grace Villiers is disappointed by an unexpected addition to their party. Then the new arrival offers to teach Grace to swim, and she is forced to see there is more to Algernon Lake than his reputation. But, with war brewing across Europe, this will be a summer that changes everything.

No one is more surprised than Meredith when she’s bequeathed a cottage by a great aunt she’d never heard of. She hopes, briefly, that the inheritance could be the answer to her financial problems. But when she arrives in Suffolk, she is shocked to discover a man is already living there. A young gardener, who claims he was also bequeathed half of Butterfly Cottage. As the pair try to unravel their complicated situation, they unearth a decades old mystery involving Clara, the garden, and a stack of letters left unread for over 50 years.

1976. Rushing out of the University Library, undergraduate Alice Kenzie bumps straight into PhD student Tristan Somers. There begins a whirlwind romance, and Alice falls pregnant and gives birth to a baby girl. Then Tristan is killed in a car accident. Unable to cope, Alice takes her baby to Summer House, Tristan's family home in Suffolk, leaves her there and disappears. 2018. Olivia Somers has always been told that her mother died in the same accident as her father. When she finds old letters in Summer House, everything she ever believed about her mother is called into question.

Tom, my husband, is always watching, controlling my every move. He chooses my clothes, my hairstyle, even instructing what and how much I’m allowed to eat – just ten measly mouthfuls. I’ve become isolated from those I love, forbidden to work and stuck at home to fulfil his every whim. My identity along with my life is long gone. I am slowly suffocating but I know Tom will never, ever let me leave alive. A chance encounter with Savannah changes everything. Tom couldn’t tear his eyes away from her. Could she be my saviour?

1952: Vivien and Max collide in the thick London smog. Within a few years, their whirlwind romance sees them living a quiet life on the Norfolk coast, blissfully happy with their beautiful daughter—at least, that's how it appears... 2019: Isobel is hoping for a fresh start when she inherits her beloved grandmother Vivien's house in Silverton Bay. But when she discovers an old photograph of Vivien at one of the infamous parties held at Silverton Hall in the 1950s, Isobel is forced to question how well she really knew her grandmother.