Iain sets sail on one of the fastest racing boats ever built to explore the story of our turbulent relationship with the wind. Travelling to iconic locations including the Sahara desert, the coast of West Africa and the South Pacific, Iain discovers how people have exploited the power of the wind for thousands of years. The wind is a force which at first sight appears chaotic. But the patterns that lie within the atmosphere have shaped the destiny of continents, and lie at the heart of some of the greatest turning points in human history.

Iain explores man's relationship with fire. He begins by embarking on an extraordinary encounter with this terrifying force of nature - a walk right through the heart of a raging fire. Fire has long been our main source of energy and Iain shows how this meant that the planet played a crucial role in Britain's industrial revolution, whilst holding China's development back. Along the way he dives in a mysterious lake in Oregon, climbs a glacier of salt, crawls through an extraordinary cave in Iran and takes a therapeutic bath in crude oil.

Dr Aleks Krotoski concludes her investigation of how the World Wide Web is transforming almost every aspect of our lives. Joined by Facebook founder Mark Zuckerberg, Bill Gates, Al Gore and the neuroscientist Susan Greenfield, Aleks examines the popularity of social networks such as Facebook and asks how they are changing our relationships. And, in a ground-breaking test at University College London, Aleks investigates how the Web may be distracting and overloading our brains.

The tour was designed by Willie Williams, who has worked on every U2 tour since 1982. Williams had been toying with ideas for 360-degree stadium staging for U2 for a number of years, and presented sketches of a four-legged design to the group near the end of their Vertigo Tour in 2006. The inspiration for the 'spaceship-on-four-legs' design, nicknamed 'the Claw', came from the landmark Theme Building at Los Angeles International Airport.

Painted over five centuries ago, Filippo Lippi's nativity is like none other: it shows the birth of Christ in a dark, wooded wilderness. There are no shepherds, kings, ox, ass – there is no Joseph. Its beauty inspired Michelangelo, Leonardo da Vinci and Botticelli. But it also conceals a deeply personal story. It was painted for Cosimo de Medici, a wealthy banker who feared that his money was dragging him straight to hell. The artist's life was equally surprising. One of the most celebrated painters of his day, Filippo Lippi was also a Carmelite friar, but he was no stranger to the temptations of the flesh, to which he frequently yielded. Shortly before painting his Adoration, he caused uproar by seducing a twenty year-old nun. His paintings rejoice not only in divine beauty, but in the beauty of women. In later times, the Adoration's history was interwoven with that of rulers and dictators. It became a bargaining chip after Napoleon's allies seized twenty merchant ships. And in the 20th century, it was hidden by the Nazis in a potassium mine, where specialist american officers, known as Monuments Men, stumbled upon it. they were now told to get it ready to be shipped out. In an unprecedented turn of events they refused. This is the only known case in the whole of the Second World War of American officers refusing an order. It was sent to the National Gallery of Art, but in 1949 Lippi's Adoration was returned to Germany.

Drazen Petrovic and Vlade Divac were two friends who grew up together sharing the common bond of basketball. Together, they lifted the Yugoslavian National team to unimaginable heights. After conquering Europe, they both went to America where they became the first two foreign players to attain NBA stardom. But with the fall of the Soviet Union on Christmas Day 1991, Yugoslavia split up. A war broke out between Petrovic's Croatia and Divac's Serbia. Long buried ethnic tensions surfaced. And these two men, once brothers, were now on opposite sides of a deadly civil war. As Petrovic and Divac continued to face each other on the basketball courts of the NBA, no words passed between the two. Then, on the fateful night of June 7, 1993, Drazen Petrovic was killed in an auto accident. "Once Brothers" will tell the gripping tale of these two men, how circumstances beyond their control tore apart their friendship, and whether Divac has ever come to terms with the death of a friend before they had a chance to reconcile.