After the death of her grandmother, reluctant heiress Madilyn Marak agrees to stay with her grandfather at the estate for the summer. There, she finds an old diary hidden in an antique desk in the attic--The Apple Diary--written by her great-grandmother Isabel.

In there, she finds the love story of Isabel and Lorah, along with a photograph of the two young women from 1933. The diary, like the love affair, was short and brief, but rich and vivid enough for her to feel a true bond with the women despite the heartbreaking ending.

She is determined to get Isabel's beloved apple orchard--which had fallen into ruins--vibrant again. She hires the inexperienced Dylan Hayes, a woman soon to be homeless, to take on the chore of restoring the orchard to its original glory.

The normally quiet and reserved Madilyn finds a new joy in life as she becomes friends with the outgoing and energetic woman who has come to live on the property. As she is transformed from a stoic and passive heiress to a happy and spirited woman, she realizes the similarities of her journey and that of Isabel's.

Like Isabel, is she destined to marry a man she doesn't love? Or will she find the strength that eluded Isabel and follow her heart?