What does it take to swim from Cuba to Florida without a shark cage? According to Diana Nyad, the answer is passion bordering on obsession. Nyad first attempted the 111-mile crossing in 1978. Thirty-five years later, at the age of 64, following four failed efforts that left her devastated, she became the first person to complete the crossing, stroking for 53 hours almost nonstop. During her swims, Nyad encountered near-deadly box jellyfish stings, horrendous saltwater chafing, hallucinations, and sea sickness. Now she's turned the experience into a one-woman play that she wants to bring to Broadway. Outside contributing editor Florence Williams drops in on the unstoppable athlete and amazing storyteller at her LA home to talk about her long journey—and where she's headed next.