Urchin tells a darkly humorous story with a wry, fairytale undercurrent. Astrid, a lonely, grubby ugly duckling, is growing up in the 60s in an elegant but ramshackle house near the University of Chicago; she is also a musical prodigy. Fortified by her passion for music, she learns to survive on the elusive love of her eccentric, wizardly old father, Otto, a famous Scandinavian mathematician who essentially lives in his attic study, as well as to resist the alluring, hollow love of her young mother, Janelle, a professor, a beauty, a lush, and a self-deluded version of the jealous queen in Snow White. Janelle’s confidante, Harriet, attempts the role of fairy godmother. Her student lover, the composer Anthony Russo, is Astrid's would-be hero.