Christa and Cara Parravani were identical twins. When they were 28, Cara died of a drug overdose, and Christa spiraled into depression.
In her new book, Her: A Memoir, Christa explores their bond of sisterhood, which went beyond blood into the elliptical world of twinhood.
Both were artists, one a writer and the other a photographer. Both married young. Both lived through a hardscrabble childhood with a troubled mother. But Cara's path diverged after she was attacked and raped at age 24.