The Roman army turns its attention to an island of rich resources, powerful tribes and druids, and advanced military equipment - Britain. This episode tells the story of the Celts' last stand against the Roman army - a revolt led by another great leader, the warrior queen Boudicca.

The global cyberwar is heating up and the stakes are no longer limited to the virtual world of computers. Now, thanks in part to secret documents released by Edward Snowden, the true scale of the National Security Agency's scope and power is coming to light. Besides spending billions of dollars to ingest and analyze the worlds' electronic communications, the NSA has set out to dominate a new battlefield—cyberspace. We examine the science and technology behind cyber warfare and asks if we are already in the midst of a deadly new arms race". Already, highly sophisticated, stealthy computer programs such as the notorious Stuxnet worm can take over and even destroy the control systems that regulate everything from food factories to gas pipelines, power plants, and chemical facilities—even our cars. While the destruction of Iranian centrifuges may have delayed Iran’s bomb program and forestalled an Israeli attack, the attack has opened a Pandora's Box, and now America's own critical infrastructure is vulnerable to retaliation and attack. With leading defense experts and investigative journalists who have probed the murky realm of criminal and strategic hacking, NOVA examines the chilling new reality of cyberwar in which no nation or individual is safe from attack.

On November 25th, 1915, Einstein published his greatest work: General Relativity. The theory transformed our understanding of nature’s laws and the entire history of the cosmos, reaching back to the origin of time itself. Now, in celebration of the 100th anniversary of Einstein’s achievement, discover the inside story of Einstein’s masterpiece". The story begins with the intuitive thought experiments that set Einstein off on his quest and traces the revolution in cosmology that is still playing out in today’s labs and observatories. Discover the simple but powerful ideas at the heart of relativity, illuminating the theory—and Einstein’s brilliance—as never before. From the first spark of an idea to the discovery of the expanding universe, the Big Bang, black holes, and dark energy, NOVA uncovers the inspired insights and brilliant breakthroughs of “the perfect theory.”

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.

The contests between predators and prey are the most dramatic events in nature. Taking an intimate and detailed look at the remarkable strategies employed by hunters to catch their prey and the hunted to escape. Sir David Attenborough narrates. "The Hardest Challenge" reveals the extraordinary range of techniques predators use to catch their prey - from a leopard using all its powers of stealth to stalk impala in broad daylight to wild dogs, whose tactic is to wear down their prey over long distances; from Nile crocodiles, the planet's most patient predators, to killer whales who use teamwork and intelligence to take on humpback whales. But even with these finely tuned strategies, the outcome is far from certain. Surprisingly, most predators fail most of the time.

The coast is the dynamic border between land and sea; powered by the tides and thrashed by waves, this is a world of continuous change. Opportunities never last long here, so hunters are always in a race against time. The coast is the only place on the planet where predators from air, land and sea come together. Dolphins that leave the safety of the sea to fish, walking octopuses, ingenious monkeys, fishing wolves and the greatest gathering of feeding humpback whales come to the coast to hunt. For all, timing is everything.