"A staggeringly beautiful meditation on love, legacy and the emotional necessities that make life worth living." (Tea Obreht, author of The Tiger's Wife). BOSTON, 1980. Ada Sibelius is twelve years old and home-schooled. Her days are spent in a lab with her father David, a computer science professor, and the brilliant minds of his colleagues. David is widely regarded as one of best in his field. That is, until he starts to forget things. When David is diagnosed with Alzheimer's, Ada's world falls apart. But when he leaves a floppy disk for his beloved daughter, she has no idea that the coding within it holds the key to a past that her father refused to talk about. Navigating her teenage years without his guidance, will Ada be able to piece together the father she lost?