The Basilosaurus, the first of the large whale species, is not a harmless plankton eater but a fearsome high speed hunter. And most frightening of all is the Megalodon, a gargantuan ancestor of the great white that makes its modern day relative look like a tuna.

In the final part, Professor Al-Khalili uncovers tales of success and heartache in the story of chemists' battle to control and combine the elements, and build our modern world. He reveals the dramatic breakthroughs which harnessed their might to release almost unimaginable power, and he journeys to the centre of modern day alchemy, where scientists are attempting to command the extreme forces of nature and create brand new elements.

Cobra Gypsies offers a contemporary and colorful window to the amazing ancient culture of the nomadic Kalbeliya tribe, living in rural Rajasthan, Northern India. Their name means 'those who love snakes'. The film explores their culture of eternal dance, syncopated music, snake charming, colorful fashion and the nomadic way of life of these exotic looking castoffs, ancestors to the modern Roma Gypsies living in Europe today.

A Japanese playing card company called Nintendo enters gaming. To stay competitive in a modernizing Japan, their portfolio expanded to include toys and into the arcade. And the company hit it big with Donkey Kong and Super Mario, then later takes over home gaming with the Nintendo Entertainment System.

We think of comets as beautiful glowing balls of light streaking across our skies with their long sweeping tails, yet comets are so much more than just a cosmic firework display. Comets have a uniquely important place in modern science. As time machines from the early universe, they could hold the key to unlock the secrets of the cosmos. Comets could even be the origin of life itself. We follow the incredible odyssey of a comet as it sails through the solar system, watching it's every move as it evolves from a dormant chunk of ice and rock into a tumbling, violently active nucleus engulfed in a gaseous haze. What we learn is a revelation; comets are even more mysterious and fascinating than we had ever imagined.

Cabeza de Vaca was shipwrecked off the coast of Texas in 1528 and lived with Indians for eight years. Upon his return to Spain, he wrote a book based on his experiences. His tale is one of empathy and respect for the Indians. Follow along as Michael Wood traces his journey.