In the third episode of the series, Morgan Freeman examines different faiths' concepts of God, discovering how monotheism began in Egypt and Israel and allowing a neuroscientist to examine his own brain.

We are the most power-hungry generation that has ever lived. This film tells the story of how that power has been harnessed - from wind, steam and from inside the atom. In the early years the drive for new sources of power was led by practical men who wanted to make money. Their inventions and ideas created fortunes and changed the course of history, but it took centuries for science to catch up, to explain what power is, rather than simply what it does. This search revealed fundamental laws of nature which apply across the universe, including the most famous equation in all of science, e=mc2.

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.

These unmanned flying robots–some as large as jumbo jets, others as small as birds–do things straight out of science fiction. Much of what it takes to get these robotic airplanes to fly, sense, and kill has remained secret. But now, with rare access to drone engineers and those who fly them for the U.S. military, we reveal the amazing technologies that make drones so powerful". From cameras that can capture every detail of an entire city at a glance to swarming robots that can make decisions on their own to giant air frames that can stay aloft for days on end, drones are changing our relationship to war, surveillance, and each other. And it's just the beginning. Discover the cutting edge technologies that are propelling us toward a new chapter in aviation history

Serial killer Dennis Nilsen narrates his life and horrific crimes via a series of chilling audiotapes recorded from his jail cell. Set against the backdrop of 1980s Britain, when mass unemployment drew young men to London in search of their fortunes, only to find themselves destitute and easy prey, and weaving together interviews from police, journalists, survivors, bereaved families, and - for the first time the killer's own voice, this feature length documentary explores how Nilsen was able to get away with multiple murders and attacks, unchallenged, for five years.

Fourth episode examines how plants either share environments harmoniously or compete for dominance within them. Attenborough highlights the 1987 hurricane and the devastation it caused. However, for some species, it was that opportunity for which they had lain dormant for many years. The space left by uprooted trees is soon filled by others who move relatively swiftly towards the light. The oak is one of the strongest and longest-lived, and other, lesser plants nearby must wait until the spring to flourish before the light above is extinguished by leaves. Tropical forests are green throughout the year, so brute force is needed for a successful climb to the top of the canopy: the rattan is an example that has the longest stem of any plant. As its name suggests, the strangler fig 'throttles' its host by growing around it and cutting off essential water and light. Some can take advantage of a fallen tree by setting down roots on the now horizontal trunk and getting nutriment from the surrounding moss and the fungi on the dead bark. The mountain ash (eucalyptus regnans) grows so tall, that regeneration becomes a considerable problem. It is easily flammable, so its solution is to shed its seeds during a forest fire and sacrifice itself. It therefore relies on the periodic near-destruction of its surroundings in order to survive. Attenborough observes that catastrophes such as fire and drought, while initially detrimental to wildlife, eventually allow for deserted habitats to be reborn.