Illustration by Anna Parini Earlier this year, I investigated the bizarre case of Guojun Xuan and Silvia Zhang, a couple from the wealthy city of Arcadia, in Los Angeles County. They had amassed more than two dozen children by hiring many surrogates who, at first, knew nothing of one another. The secrecy and suspicious circumstances surrounding Xuan’s family prompted an F.B.I. investigation into whether he and his partner were trafficking the children.