You mean the river of forgetting in the Greek Underworld? That's a real place?!
[She looks excited. Sarah lives in her books, and this sort of thing is really exciting for her.]
Jareth? He's the Goblin King. I accidentally wished my brother to the Goblins, and he took him. I didn't want him to actually take my brother though, and I had to get him back. So Jareth took me to the Labyrinth... told me I could get my brother back if I got to the center of the Labyrinth in 13 hours.