The episode is a journey through the human gut and the process of turning food into energy to keep the body going. Humans have turned eating into culture, a way to celebrate our roots, to bring us together. But food is really just one thing: Fuel. It's where you get the power to live your life. Even when you're sitting completely still, your body needs a lot of energy to stay on. But nowhere is the need for fuel more apparent than when you push yourself to the absolute limit. And the microbiome, the bacteria living in our gut, plays a great role in all this.

A bizarre 3,000 year-old gold relic crafted with intricately designed cryptic patterns is believed to form a highly complex celestial code; using advanced imaging technology, experts speculate that it could be an ancient device for predicting the future.
Professor Timothy Koeth at Maryland University received a package containing a curiously heavy two-inch black cube. It comes with a message: "Taken from Germany from the nuclear reactor that Hitler tried to build."

In the Taurus Mountains Simon stays with descendants of the original Turks, nomads known as Yoruks, whose lifestyle is under threat from the modern world and an increasingly religious government. They're not the only minority at odds with the authorities in Turkey; Simon sees first-hand the devastating effects of fighting in the country's Kurdish region. In an area where the government has detained foreign journalists, Simon gathers unique footage in the aftermath of a crackdown on Kurdish militants - the wholesale destruction of the historic centre of one of Turkey's oldest cities.
Away from the conflict in the south, Simon heads towards the Black Sea coast. He meets a wildlife conservationist protecting Turkey's population of brown bears, and villagers who still communicate over long distances using an ancient bird language. In the country's capital he meets a victim of President Erdogan's authoritarian purge of people accused of complicity in the failed coup against him.
Finally Simon's journey comes full circle when he returns to Istanbul - home to the new craze of 'Ottomania', a celebration of the vast empire that preceded modern Turkey. Simon visits the set of one of the world's most popular TV dramas - even getting a speaking role - based in the court of an Ottoman sultan

The archaeological world is fooled for nearly half a century when an ape-like skull that's claimed as solid evidence for Darwin's theory of human evolution is proven fake. Using new research, experts investigate and uncover the identity of the forger.
Locked away in a store room at London Science Museum is a genuine 19th century miracle machine, a 180-year-old mechanical engine that solves complex mathematical equations, more than 100 years before the first electronic computer.

The jeweled-encrusted pectoral of King Tut is a hieroglyphic artefact of stunning craftsmanship and one of the greatest treasures of the pharaohs. Was this ancient glass scarab in Tutankhamun's tomb created by forces from beyond our world? Using new research and the latest tech, experts confront the ancient mystery of its flawless glass scarab.
Is a 4,000 year old clay tablet the original instruction manual for Noah's ark? And how can a bizarre red moon rock contain signs of life?

The Namib Desert is one of the oldest deserts and also one of the most diverse. With 50ºC (120ºF) temperatures and half a millimetre of rainfall annually, we see how this is possible. Half the size of Oklahoma, from its Skeleton Coast through the sea of sand to the haze of distant mountains this apparently forbidding desert hides secret water sources.