As Allen Shawn probed the sources of his anxieties while writing the acclaimed Wish I Could Be There, he realized that his fate was inextricably linked to his autistic twin sister. Mary, who has lived in a residency center for more than fifty years. Twin offers a deeply personal account of their divergent lives, and examines society's changing attitudes toward and understanding of autism. It also provides an intimate look at the Shawns' idiosyncratic family life with their father, the famed longtime editor of The New Yorker, William Shawn. Wrenching, honest, understated, and poetic, Twin is at heart about the mystery of being profoundly bonded to someone who can never be truly understood.