In 1961, off the mangrove-choked coast of Dutch New Guinea, a young man stripped to his underwear and swam for help using two empty gas cans as a float. He was Michael Rockefeller, heir to one of the greatest fortunes in American history, and after he vanished over the horizon he was never seen again. This episode maps how a life of unimaginable privilege ended in a mystery that has gripped the world for over six decades.

Rather than take a corner office, Rockefeller was drawn to the Asmat people and their art, joining a Harvard Peabody expedition before returning independently to trade for artifacts. When his catamaran capsized on the Arafura Sea, he drifted a day and a half before deciding to swim, launching two starkly different explanations for his fate.

• His pedigree included Phillips Exeter, Harvard, and a father, Nelson Roc ...