Singing the Body Electric

He actually didn't! We learn fairly early on that he's alive, having gone on the run after being accused of theft by his former employer. The question of whether he's really innocent and whether Polly will see him again before she's grown is then more of a focus throughout the first book— or a sort of secondary focus, since the story's more about her getting on with her childhood amidst the fallout from the adults' choices around her.