We are in the grip of an allergy epidemic. 50 years ago one in 30 were affected, but in Britain today it is closer to one in three. Why this should be is one of modern medicine's greatest puzzles. In search of answers, Horizon travels round the globe, from the remotest inhabited island to the polluted centres of California and the UK. We meet sufferers and the scientists who have dedicated their lives trying to answer the mystery of why we are becoming allergic to our world.

With the killer's identity - and twisted motives - revealed, the group finds more key clues as the global police manhunt reaches a fever pitch. A question arises: Were we complicit in his crimes? Did we feed the narcissism of the monster to the point where he had to go forward?

For 45 years, America was locked in the Cold War with the Soviet Union, and fear of global nuclear annihilation was constant. The end of the Cold War in 1991 was supposed to usher in a new era of peace and cooperation, but it didn’t last. Tensions between the U.S. and Russia have been simmering for years. And now, the conflict in Ukraine has pushed the relationship to the brink of full-blown crisis. VICE Founder Shane Smith met Kremlin officials and American leaders to figure out what’s really driving the new standoff between the powers, while correspondent Simon Ostrovsky reported from the front lines of the bloody war in Eastern Ukraine.

Professor Brian Cox concludes his exploration of our place in the universe by asking what next for the ape that went to space. Our future is far from certain. In Florida, Brian joins the latest efforts to protect Earth from potential catastrophic events. He joins a team of Nasa astronauts who are training for a future mission to an asteroid - should we ever discover one coming our way - under 30 feet of water in a submerged laboratory that simulates space. It is just one example of how, for our long-term survival, space exploration may well be vital. It is a view shared by Apollo 16 astronaut Charlie Duke, who tells Brian what it was like to escape the confines of the planet. It is a dream that both Nasa and now commercial companies share as they race to get humans back into deep space.
But space travel, like every leap our civilisation has ever made, requires energy. Here too, scientists are hard at work attempting to safeguard our future. At the National Ignition Facility in California, Brian witnesses the world's most successful fusion experiment in action. He believes that if their mission succeeds, our civilisation will have unlocked a way to the stars that will not destroy the planet in the process. Brian concludes by returning to the top of the world in Svalbard, where he gains access to our civilisation's greatest treasure, locked away in a vault buried deep in the permafrost.

Playing with Nuclear Fire' - In March 2011, the Tohoku earthquake in Japan created a tsunami that killed some 16,000 people and crippled the Fukushima Daiichi nuclear power plant. In the aftermath, the government and TEPCO, the plant's operator, withheld information about the extent of the damage. Three years later, citizens and the international community are left wondering if Japan really does have the situation under control, as the government is insisting, or if the danger is far greater than anyone is willing to admit. 'No Man Left Behind' - It's estimated that over a quarter million vets from recent wars have sought treatment for PTSD. Despite these statistics, veterans often face an uphill battle to get treatment, receiving inadequate attention and, most dangerously, overprescribed narcotics and other pharmaceuticals. Ryan Duffy meets veterans struggling with mental illness and addiction.

In Egypt, Caesar rebukes the advisers of the boy king, Ptolemy XIII, for their presumption in eliminating Pompey and demands the man who killed him. Caesar decides to intervene in the dispute between Ptolemy and his sister-wife, Cleopatra, to ensure both Rome's grain supply and his own access to Egypt's treasure.
Antony, in an unusual show of prudence, advises against this with only half a legion in Alexandria and Cato and Scipio still at large in Africa. In Rome, Brutus gets a chilly reception from Servilia when he returns home from Greece.