"We are all the sum of various parts," wrote Romain Gary in Hocus Bogus.Rachel Khan knows this only too well. Black, Gambian, Muslim, and Catholic on her father's side, and white, Jewish, and French on her mother's, she is proud to call herself "race-y." But how to live with this profusion of "races" at a time of identity-based withdrawal, when only radicalism matters? How to position oneself with such a "pedigree" when orders are to pick a side?