Amy Purdy & Derek Hough do the Quickstep on Dancing with the Stars season 18 Week 9.https://www.youtube.com/watch?v=bTnqF9mpVdoncG1vNJzZmivp6x7tbTEoaalpKmsvLCwxqiqrKGgY7CwuY6voJ2dn6h8ornYZqeuqpSueqK6w2abnqqVoHqpu9Sgn2appZ6wrL%2FTnqdo