Derek Hough was ready to bid adieu to his Dancing gig – but then he heard Purdy's remarkable story. "I instantly wanted to be a part of that journey," he says of pairing with the athletic double-amputee. "Any woman who has overcome those sort of odds and defied them inspires me. It's given a new meaning and purpose for me to be part of the show. I want to see how far we can take this."