In 1973, six women and five men climbed aboard a small raft to cross the Atlantic Ocean. It was part of a radical experiment by the Mexican anthropologist Santiago Genovés. Inspired by the Vietnam War and the peace movement, he wanted to investigate whether human beings are naturally aggressive and warlike. The guinea pigs were carefully selected to include a wide variety of origins and backgrounds, and because he supposed that there was a connection between aggression and sex, he consciously picked the most attractive candidates—leading the media to dub the experiment “the sex raft.” Through extraordinary archival material and a reunion of the surviving members, this film tells the hidden story behind what has been described as “one of the strangest group experiments of all time.”