Placebos come in all shapes and sizes, but they contain no active ingredient. They are the miracle pills that shouldn't really work at all. Now they are being shown to help treat pain, depression and even alleviate some of the symptoms of Parkinson's disease. It seems they're not acting alone. The placebo effect is intertwined with how is did the healthcare. Explores why they work, and how we could all benefit from the hidden power of the placebo.

Can we find a way to distribute power so that everyone has their say? A U.S. president explains the challenges of making decisions that affect hundreds of millions of lives, and Freeman learns about an African woman who has created a society without men. He explores how the rise of the internet may fundamentally change how democracy works.

The world couldn't keep its eyes off two athletes at the 1994 Winter Games in Lillehammer - Nancy Kerrigan, the elegant brunette and Tonya Harding, the feisty blonde engulfed in scandal. Just weeks before the Olympics on January 6, 1994 at the U.S. Figure Skating Championships, Kerrigan was stunningly clubbed on the right knee by an unknown assailant and left wailing, 'Why, why, why?'
As the bizarre 'why' mystery unraveled, it was revealed that Harding's ex-husband, Jeff Gillooly, had plotted the attack with his misfit friends to literally eliminate Kerrigan from the competition. Now two decades later, The Price of Gold takes a fresh look at the worldwide spectacle that elevated the popularity of professional figure skating and has Harding still facing questions over what she knew when she knew it.

In the final episode, we hear how employees on the 17th floor were rewarded, and we see Madoff's $65 billion Ponzi scheme quickly collapses as investors begin to withdraw their money during the 2008 Financial Crisis. We see how Madoff's sons attempt to stop their father from writing bonus cheques for long-time investors, faithful employees, and extended family to help cushion the blow. Madoff confesses to the Ponzi scheme, and the FBI arrests him.
After pleading guilty, Madoff is sentenced to 150 years in prison. Two years after learning of the Ponzi scheme, his eldest son Mark is found hanging from a pipe, dead of an apparent suicide. His other son dies of lymphoma six years later.

The five directors, John Ford, William Wyler, John Huston, Frank Capra, and George Stevens, return to Hollywood after the war but are forever haunted by what they saw. Ford goes on a drinking bender after filming the carnage at D-Day. Stevens is wholly unprepared for the horrors of Dachau and realizes he is not there to film propaganda but to capture evidence of crimes against humanity. Wyler, who lost his hearing during the war, fears his career is over. Huston chronicles soldiers suffering from postraumatic stress disorder in the film Let There Be Light, only to have it suppressed by the U.S. government.

The fifth programme explores the alliances formed between the animal and plant worlds. Attenborough dives into Australia's Great Barrier Reef and contrasts the nocturnal feeding of coral, on microscopic creatures, with its daytime diet of algae. Some acacias are protected by ants, which will defend their refuge from any predator. Besides accommodation, the guards are rewarded with nectar and, from certain species, protein for their larvae as well. Fungi feed on plants but can also provide essential nutriment to saplings (Mycorrhiza). The connection is never broken throughout a tree's life and a quarter of the sugars and starches produced in its leaves is channelled back to its fungal partners. Meanwhile, fungi that feed on dead wood leave a hollow trunk, which also benefits the tree. Orchids enjoy a similar affiliation. Lichens are the product of a relationship between fungi and a photosynthetic associate, usually algae. They are extremely slow-growing, and a graveyard is the perfect location to discover their exact longevity. Mistletoe is a hemiparasite that obtains its moisture from a host tree, while using own leaves to manufacture food. Its seeds are deposited on another by the mistletoe tyrannulet, following digestion of the fruit. The dodder (Cuscuta) is also parasitic, generally favouring nettles, and siphons its nourishment through periodic 'plugs' along its stem. The rafflesia has no stem or leaves and only emerges from its host in order to bloom — and it produces the largest single flower: one metre across.