March 5, 2009— -- In a town full of big names, Siegfried and Roy's became the biggest. With their menagerie of exotic tigers and lions, these self-proclaimed "masters of the impossible" earned more money than any other act in the history of Las Vegas. At their peak they brought in $57 million a year.
But their career nearly came to an end when a tiger dragged Roy Horn offstage in October 2003. He has been recuperating since then, and still faces many obstacles.
Watch Siegfried & Roy's final performance in "Siegfried & Roy: The Magic Returns," a special edition of ABC News' "20/20," Friday, March 6 at 9 p.m. ET
In a revealing interview with "20/20" co-anchor Elizabeth Vargas, the illusionist pair opened up about Horn's dramatic five-year rehabilitation.
But Horn, who is now 64 years old, wasn't the only one who was affected by the accident; Siegfried Fischbacher, now 69, was also struggling to hang on, overwhelmed by the injury to his friend and what that injury meant to the only thing he really loved ... his magic show.
"I was so alone, and I was so lost," he said. "And, of course, I got in depression, but the depression was more because of the show ... because it was over."
Saturday's performance raised more than $10 million for the state-of-the-art medical facility, which is under construction in Las Vegas. The Institute was developed to treat brain diseases such as Alzheimer's, Lou Gehrig's and Parkinson's.
"I'm at a part of my life now where I think I can give something back," Fischbacher said. "And this country and Las Vegas was so good to me for 45 years, and I think that was a perfect reason to do it."