despa despairing, the isolated. reporter: the state department admits there are slaves hidden in plain sight in the united states. at the national human trafficking hot line center in washington d.c., bradley myles hears one name over and over again as a source of this brutal slavery. multiple victims are saying, i came through a mexican down. referred to by many as the sex trafficking city of the world. this small village in mexico is said to have been overrun by human traffickers. they started telling us the sex acts for $30 for have a minutes of sex. they ve been on shift. that was a volume of frequency of different customers that we had never heard of before.