van zeller.ives into is complex and dangerous global underworld. so nice to see you safe and sound. i always feel like you're so intrepid. you are our girl crush on the show, friend of "nightline." let's talk about "traffic." it is explores the dark corners of the world and everything from assassins to narco terrorists to those who traffic in body parts. so as a journalist, what keeps drawing you to these dark corners? >> i've always been fascinated by sort of -- i think as a journalist, you'd understand when they tell you there's a dark, secretive world, a part of the world you can never get into, that's where you want to go. >> juju: sure. >> i've always been super attracted and fascinated by these worlds. people don't know these black and gray markets make up half the world's economy, yet we know so little about them. from the beginning, i think i started doing this, covering black markets for over 20 years now. and yeah, it's always drawn me. >> juju: this is season four of "trafficked." epis