In the third part of his journey into the history of Christianity, Professor Diarmaid MacCulloch charts Orthodoxy's extraordinary fight for survival. After its glory days in the eastern Roman Empire, it stood right in the path of Muslim expansion, suffered betrayal by crusading Catholics, was seized by the Russian tsars and faced near-extinction under Soviet communism. MacCulloch visits the greatest collection of early icons in the Sinai desert, a surviving relic of the iconoclastic crisis in Istanbul and Ivan the Terrible's cathedral in Moscow to discover the secret of Orthodoxy's endurance.

Narrated by Ewan McGregor, Humpback Whales is an extraordinary journey into the mysterious world of one of nature's most awe-inspiring marine mammals. Set in the spectacular waters of Alaska, Hawaii and the remote islands of Tonga, this ocean adventure offers audiences an up-close look at how these whales communicate, sing, feed, play and take care of their young. Humpbacks were nearly driven to extinction 50 years ago, but today are making a slow but remarkable recovery. Join a team of researchers as they unlock the secrets of the humpback and find out why humpbacks are the most acrobatic of all whales, why they sing their haunting songs, and why these intelligent 55-foot, 50-ton animals migrate up to 10,000 miles round-trip every year.

Take a look at the issues that will change the way we live our lives in the future. Hannah Fry delves into the data we have today to provide an evidence-based vision of tomorrow. With the help of science experts Hannah tries to discover whether we could ever live forever or if there will ever be a cure for cancer. She finds out how research into the human brain may one day help with mental health, and if it is possible to ever ditch fossil fuels. Hannah and her guests also discover the future of transport - and when, if ever, we really will see flying cars. She discovers whether a robot will take your job or if, as some believe, we will all one day actually become cyborgs. The programme predicts what the weather will be like and discovers if we are on the verge of another mass extinction. Hannah's tenth prediction is something she - and Horizon - are confident will definitely happen, and that is to expect the unexpected!

40,000 years ago the steppes of Eurasia were home to our closest human relative, the Neanderthals. Recent genetic and archaeological discoveries have proven that they were not the dim-witted cave dwellers we long thought they were. In fact, they were cultured, technologically savvy and more like us than we ever imagined! So why did they disappear? We accompany scientists on an exciting search for an answer to this question and come to a startling conclusion... A climate change due to a cataclysmic event.

Sagan discusses the story of the Heike crab and artificial selection of crabs resembling samurai warriors, as an opening into a larger discussion of evolution through natural selection (and the pitfalls of intelligent design). Among the topics are the development of life on the Cosmic Calendar and the Cambrian explosion; the function of DNA in growth; genetic replication, repairs, and mutation; the common biochemistry of terrestrial organisms; the creation of the molecules of life in the Miller-Urey experiment; and speculation on alien life (such as life in Jupiter's clouds). In the Cosmos Update ten years later, Sagan remarks on RNA also controlling chemical reactions and reproducing itself and the different roles of comets (potentially carrying organic molecules or causing the Cretaceous–Paleogene extinction event).

Asteroids strike, planets collide, black holes blast out death rays, volcanoes erupt and ice engulfs the planet. These are the universe's weapons of extinction. They've happened before - wiping out entire species, and they will happen again. Are we next?