Fifteen-year-old Catherine Quick longs to feel once more the warm waters of her home, to strike out into the ocean off the Torres Strait Islands in Australia and swim, as she’s done since she was a child. But now, orphaned and living with her aunt Louisa in London, Catherine feels that everything she values has been stripped away from her. Louisa, a London surgeon who fought boldly for equality for women, holds strict views on the behavior of her young niece. She wants Catherine to pursue an education, just as she herself did. It takes the enigmatic American banker Manfred Lear Black to convince Louisa to bring Catherine to New York where Catherine can train to become the first woman to swim the English Channel.

Iris Crane’s tranquil life is shattered when a letter summons memories from her bittersweet past: her first love, her best friend, and the tragedy that changed everything.