England, 1918. As war ends, across the world people are trying to heal and recover. But Eleanor still feels broken. The loss of her beloved brother, killed just days before the Armistice was signed, feels impossibly unjust. Spending her time in the neglected garden behind their house, she fears her heart will never recover.

Then her father hires a man to help restore the garden to its former glory. Gruff, handsome Yorkshireman Jack comes from a totally different world to Eleanor, but he understands the nature of her grief more than anyone else seems to. And as they spend time together, she starts to wonder if there's any way for her to learn to soar again...

Now. Nearly one hundred years later, Marin is not prepared to find herself the guardian of her fifteen-year-old half-sister Rebecca after her father and his second wife are killed in a tragic accident. The sisters are practically strangers, and Rebecca’s grief makes her seem even more distant. Marin, too, is in need of a fresh start, so when Rebecca begs her to let them move to the picturesque village of Goswell on the Cumbrian coast, Marin impulsively agrees. But it is only when they find a locked door to a secret garden and a photograph of a girl with a butterfly landing on her hand that the sisters start to realize they have a mystery to solve—one about war, about secrets, and about a love that could never be—a mystery that might just bring them together…