Marc Petitjean sheds new light on Frida Kahlo's only trip to Paris. The politically active, nonconformist, bisexual artist, rediscovered by feminist in the U.S. and Europe in the 1980s, remains in many ways a mystery. Who was this Michel Petitjean fellow she loved? What was their affair like, in the company of André Breton, Pablo Picasso, Dora Maar, and Marcel Duchamp? And why did she give him her enigmatic and highly intimate painting The Heart?