S1, E3: Whether on four legs or four wheels, they were the fastest in their sports. Secretariat made history as a Triple Crown winner in 1973, and Dale Earnhardt brought NASCAR to the masses, thanks to his fierce skill and passionate attitude. But a mystery looms over both icons, one that the Sports Detectives are determined to solve. Follow Lauren Gardner to Louisville as she searches for Secretariat's missing saddlecloth from his Kentucky Derby win. Then join Kevin Barrows' hunt for Earnhardt's unusual first racecar: a bright pink Ford.