Marlowe and Harper share a bond deeper than most sisters. For Harper, living with what she calls the Up syndrome and gifted with an endless capacity for wonder, Marlowe and she are connected by an invisible thread, like the hum that connects all things. But then Marlowe receives the devastating call that Harper's heart is failing. She needs a heart transplant. Intensely moving, exquisitely written and literally humming with wonder, it is a novel that celebrates life in all its guises, and what comes after.