It is 1912. Elsa Pendleton, a young Englishwoman, is forced by circumstance into a marriage of convenience. Her one consolation is that she can join her husband on a unique expedition: to visit Easter Island and study its mysterious history. But as Elsa becomes bewitched by the island and engrossed in her work, she doesn't realise that her beloved sister Alice is caught up in desires of her own. Not, in their isolation, do the two sisters realise that Britain and Germany have declared war, and that the catastrophic effects will be felt even in their quiet corner of the South Pacific.

Sixty years later American botanist Greer Faraday, recently widowed, arrives on the island. Troubled by unhappy memories, Greer wraps herself up in her work, rejecting the friendly approaches of her colleagues. But as the island gives up its secrets she is forced to confront some unwelcome truths of her own and her story becomes irresistibly entwined with Elsa's.