Follow filmmakers Dereck and Beverly Joubert as they travel down a river in a remote corner of Botswana and tell the story of two bull elephants that lived into their 70s. The Jouberts discovered the skulls of the old bulls with their tusks still intact, indicating that they had died of natural causes and not at the hand of ivory poachers. Finding undisturbed elephant remains is a rare event, but is more likely in Botswana, which boasts an elephant population of more than 130,000, the largest of any African country.