La mer means, simply, 'the sea.' Ludo came up under mentors like Alain Passard and Mark Meneau, chefs with an almost pathological obsession with ingredients. His eyes light up when he describes the Lobsters of Brittany, the Oysters from Cancale, and the myriad of other extraordinary culinary jewels.
In this episode, we explore how the oceanic bounty of France is some of the best anywhere by profiling the ingredients that can be pulled from it.

Through the mountains and jungles of Colombia, Cooper goes in search of the truth behind one of the greatest stories ever told - the legend of El Dorado. His journey takes him from Bogota to the Caribbean coast, through territories once dominated by two cultures, the Muisca and the Tairona, who flourished for centuries before the arrival of the Spanish in the 16th century. Cooper reveals forgotten peoples who valued gold in a way the Western world still struggles to understand, travelling to an astonishing lost city and meeting the last survivors of an ancient civilisation.

In late Cretaceous Canada, in what will be known as Dinosaur Provincial Park, a Daspletosaurus stalks a Chasmosaurus in a forest, but loses the element of surprise and is forced to retreat. The Chasmosaurus comes across a younger Daspletosaurus, before being ambushed by a group of the tyrannosaurids. The episode then cuts to the high Arctic, where Edmontosaurus are hunted by a large species of Troodon. The theropods attack at night, separating a juvenile from the herd and severely wounding it, only to be driven away by an adult. In the morning, they return to eat the carcass of the juvenile, which died during the night. The episode returns to the Daspletosaurus, who chase and bring down the Chasmosaurus. The larger adults bully the youngsters off the carcass, forcing them to wait until they have finished. The episode then cuts to Madagascar, where a mother Majungasaurus (an Abelisaurid) and her two offspring chase a group of Rahonavis off a carcass. However, they are temporarily driven off themselves by a male Majungasaurus. But, after he steals some food from one of the young, the female attacks him, before she and her young cannibalise his body. The episode returns once again to North America, where the Daspletosaurus are waiting for the annual migration of Centrosaurus. They attack during a rainstorm, killing some of the ceratopsians. The Centrosaurus make it to a flooded river and begin to swim across, and although many make it to the other side, some are caught by giant crocodilians or are severely wounded by floating debris and thus drown, or drown for unseen reasons. In the morning, the carcasses attract scavengers, including the Daspletosaurus. A montage is then shown of Daspletosaurus and Majungasaurus, the narrator saying that together, the tyrannosaurids and abelisaurids were the last of the killer dinosaurs.

During the chaotic final weeks of the Vietnam War, the North Vietnamese Army closes in on Saigon as the panicked South Vietnamese people desperately attempt to escape. On the ground, American soldiers and diplomats confront the same moral quandary: whether to obey White House orders to evacuate U.S. citizens only--or to risk treason and save the lives of as many South Vietnamese citizens as they can.

Tony Accardo receives a phone call from Joseph P. Kennedy, asking the mob kingpins to use their pull with the Illinois union vote to help his son, John F. Kennedy, win the upcoming presidential election. In return, he offers to put an end to his son Robert F. Kennedy's investigation into Giancana and the Outfit. As election day nears, Kennedy's fight against Richard Nixon tightens, turning Illinois into a key battleground. Giancana delivers the union votes. After a close race, Kennedy is declared the victor. Just weeks after Kennedy takes office, his brother Robert is named Attorney General. To the Chicago mob's surprise, when Robert takes office as the new U.S. Attorney General in 1961, he makes his top priority going after organized crime ó and one of his primary targets is the Outfit. Weeks after, John F. Kennedy is shot and killed in Dallas. After his brother is assassinated, Robert steps down from his post as Attorney General and the investigation into organized crime is virtually dropped. The government begins an investigation into the assassination, with rumors already circulating that the mafia could have been involved.

The Roman army turns its attention to an island of rich resources, powerful tribes and druids, and advanced military equipment - Britain. This episode tells the story of the Celts' last stand against the Roman army - a revolt led by another great leader, the warrior queen Boudicca.