I woke up this morning, the day of Barbara's funeral, and I fell out of bed.

And so begins the tale of one-hundred-and-one-year-old Martha Mayhew. Born in southern New Hampshire in the early 1920s, Martha meets her new neighbor Barbara Brown at the tender age of three and a half. The two girls learn immediately that they are bound to each other, and as the years progress, their friendship blossoms.

But though Martha's home is loving and supportive, she learns quickly that Barbara's is not. Why does Mr. Brown do the things he does? And why, too, does Barbara's older brother, Robert, make Martha feel so internally uncomfortable?

With Barbara at her side, Martha grows into a young woman, falls in love, and maneuvers a nuanced life filled with both tenderness and heartbreak—from the Great Depression to World War Two to Vietnam and to the AIDS epidemic of the '80s.

When you are bonded to another as Martha is to Barbara, you feel their happiness and sorrow as well as your own—explicitly and undeniably. They are intertwined, and it is together that lessons are absorbed and hearts learn to heal.