In the spring of 1974, Calliope Stephanides finds herself drawn to a classmate at her girls' school in Grosse Point, Michigan. That passion -- along with her failure to develop -- leads Callie to suspect that she is not like other girls. The explanation for this is a rare genetic mutation -- and a guilty secret -- that have followed Callie's grandparents from the crumbling Ottoman Empire to Prohibition-era Detroit and beyond, outlasting the glory days of the Motor City, the race riots of 1967, and the family's second migration, into the foreign country known as suburbia. Thanks to the gene, Callie is part girl, part boy. And even though the gene's epic travels have ended, her own odyssey has only begun.