David Attenborough returns to the island of Madagascar on a very personal quest. In 1960, he visited the island to film one of his first ever wildlife series - Zoo Quest. Whilst he was there, he acquired a giant egg belonging to an extinct bird known as the 'elephant bird' - the largest bird that ever lived. It has been one of his most treasured possessions ever since. Fifty years older, he now returns to the island to find out more about this amazing creature and to see how the island has changed. Could the elephant bird's fate provide lessons that may help protect Madagascar's remaining wildlife?
Using Zoo Quest archive and specially shot location footage, this film follows David as he revisits scenes from his youth and meets people at the front line of wildlife protection. On his return, scientists at Oxford University are able to reveal for the first time how old David's egg actually is, and what that might tell us about the legendary elephant bird.

To our medieval forebears the world could appear mysterious, even enchanted. Sightings of green men, dog heads and alien beings were commonplace. The world itself was a book written by God. But as the Middle Ages grew to a close, it became a place to be mastered, even exploited.

We call them 'man’s best friend', but their story is almost as old as man himself. Our very first friend in the world, they have walked by our side for over 20,000 years, helping us to hunt for food and offering us companionship and protection. Man’s First Friend is an epic new primetime documentary event that combines natural history, science and anthropology to explore the enduring relationship between humankind and dogs, how the two species have co-evolved together, where did they come from to take such a prominent position in our lives, and how did we learn to harness their unique talents.
The film takes viewers on an extraordinary journey through some of the most remote locations in the world to answers these questions and more. It highlights what dogs are capable of: from the Pariah dog in India who protects her owner’s banana plantations from daily attacks by Black-headed Monkeys; to Kenyan Bloodhounds trained to track ivory poachers. Dogs comfort us, relieving loneliness and helping us cope with old age.

Time travel is not forbidden by the laws of nature, but to build a time machine, we would need to understand more about those laws and how to subvert them than we do now. And every day, science does learn more. In this film Horizon meets the scientists working on the cutting edge of discovery - men and women who may discover how to build wormholes, manipulate entangled photons or build fully functioning time crystals. In short, these scientists may enable an engineer of the future to do what we have so far been only able to imagine - to build a machine that allows us travel back and forward in time at the touch of a button. It could be you! Science fiction? Watch this film.

Bitcoin is the world's leading virtual currency, but unlike real money, it is not backed by a government or properly regulated. Bitcoin is exchanged and held digitally by users - which is attractive to criminals selling drugs, pornography and arms. But now Bitcoin is moving into the mainstream and being openly marketed as an investment opportunity. The film investigates what Bitcoin is and what it means, going inside a Bitcoin mine in Iceland - where currency is made - and spending time with the Bitcoin millionaires of Silicon Valley.
The programme also hears from others who have been scammed out of their life savings and investors who think the cryptocurrency is an enormous scam and that the writing is on the wall. Around the world, authorities are sounding the alarm that Bitcoin is too risky - is it too late, or too crazy, to try to become a Bitcoin millionaire?

Dr Adam Rutherford takes the viewer on a rollercoaster ride as he explores the consequences of one of the biggest scientific projects of all time - the decoding of the entire human genome in 2000. In The Book of Life Adam discovers that every human carries the entire story of life on earth hidden in his or her DNA and sees how we are all linked directly to the origins of life and to the first creatures with backbones. He also investigates the implications of the fact that for much of its existence, the human race was an endangered species.