>> i happened to flip over an article that was on seabiscuit and there's an article on louis zamperinide. and i read it and was immediately fascinated. >> reporter: but she could never travel from her home in washington, d.c. to los angeles to meet louis. to meet louis. laura suffers from a severely incapacitating condition that has left her with constant vertigo and exhaustion so profound that for years, she was housebound. so, she and louis had marathon telephone conversations. >> and when he was telling me his story, i wasn't looking at a 95-year-old man. i was looking at the 26-year-old on a raft, you know? and i was looking at the teenager who's trying to run in the olympics. and i think it became an advantage to me in -- in telling the story that i -- i wasn't physically with him. >> reporter: "unbroken" the book, now out in paperback, has been on the best-seller list for almost four years. >> we try to then expand on this already very impressive life that laura so beautifully detailed in her book, and try to carry it forward and do nothing, nothing, to -- to hurt it. >> reporter