This is the ultimate hidden kingdom - the urban jungle. In the colourful and chaotic streets of Rio, a young marmoset is separated from his street gang and forced to confront of the dangers of the city alone. In the futuristic metropolis of Tokyo, a rhinoceros beetle escapes his captors and begins an extraordinary journey through this alien world to find sanctuary.

Today, the topic of climate change is a major part of daily life, yet 40 years ago it was virtually unheard of. Since then, Horizon have followed scientists as they have tried to unpick how the climate works and whether it is changing. Dr Helen Czerski delves into this unique archive to chart the transformation of a little-known theory into one of the greatest scientific undertakings in history. It has been a constantly surprising journey of discovery that has revolutionised our understanding of climate, and seen scientists face unprecedented controversy and criticism.

During 1942, the Red Army moved from defeat to victory.

The great apes which include chimps, orangutans, gorillas and bonobos, seem to have rich emotional lives similar to our own. But just how smart are these animals? A new generation of investigators are converging on an explanation for why the non-human great apes never made the breakthrough into an accelerating human-style culture that builds on the achievements of previous generations.

The Greek tale of Jason and the Golden Fleece has been told for 3,000 years. It's a classic hero's quest tale - a sort of ancient Greek mission impossible - in which the hero embarks on a sea voyage into an unknown land, with a great task to achieve. He is in search of a magical ram's fleece, which he has to find in order to reclaim his father's kingdom of Iolkos from the usurper King Pelias. Michael Wood discovers a story of heroism, treachery, love and tragedy that would make Hollywood proud.

Michael Wood’s epic series moves on to the revolutionary years after 500BC - the Age of the Buddha. Travelling by rail to the ancient cities of the Ganges plain, by army convoy through Northern Iraq, and on down the Khyber Pass, he shows how Alexander the Great’s invasion of India inspired her first empire.