At the beginning of the twentieth century the world was stable and certain, but unequal. The Paris Exhibition of 1900 symbolises the optimism of a peaceful age when affluence is rising and people have faith in new technologies like electricity. The United States becomes the most powerful country in the world, destination for many immigrants from Europe. Compulsory education in many countries had led to a literate population exposed to new ideas, leisure and consumerism through newspapers. Trade unions grow in strength and force governments to protect employment conditions for workers, while suffragettes push for votes for women. Revolutions shake the political order in China and Russia. European empires continue to dominate the globe, however signs of dissent appear in India and South Africa, and Japan's victory over Russia in 1905 challenges the belief of white superiority. Nationalism rises in Europe, bringing the continent to conflict in 1914.

The Great War is fought with larger armies and deadlier weapons than ever before, bringing death and carnage on an unprecedented scale to Europe. The bloody Battle of the Somme and the Battle of Verdun fail to break a stalemate on the Western front, and soldiers become increasingly frustrated and demoralised with the war's mounting casualties, poor living conditions and lack of progress. Despite the October Revolution knocking Russia out of the war in 1917, the odds shift against a blockaded Germany with the entry of the United States into the war, and eventually an armistice is signed. The psychological scars of this war would make the public less willing in future to go to war, or trust their leaders. The introductory scene shows soldiers mobilising at the beginning of the war, grossly under-estimating the destructive power of modern warfare. Interviewees include Karl von Clemm, Edward Smout and Cecil Lewis.

The October Revolution brings forth a new Marxist-Leninist society in what becomes the Soviet Union. Its people, now freed from feudal exploitation and provided with health care and education from the state, have their revolutionary zeal directed towards developing and modernising their new country. However after Vladimir Lenin's death Joseph Stalin rules with an iron fist – his attempts to collectivise farms leads to the Ukrainian famine and the mass liquidisation of kulaks. Stalin grows increasingly paranoid and ruthless, and is responsible for the deaths or expulsion to Siberia of millions of Soviets. The introductory scene explains the events leading up to the 1917 revolution. Interviewees include Anna Larina and Boris Yefimov.

The trauma of the First World War gives Europe no appetite for any further conflicts, but within subsequent two decades the world would return to rearmament and militarism. The Paris Peace Conference introduced the concept of self-determination, leading to the establishment of Czechoslovakia, Poland and Yugoslavia from the former Central Powers. The League of Nations is established to assist in resolving international disputes in an open environment, but fails to receive strong support and is eventually provent impotent in preventing Italy's conquest of Ethiopia. Despite a public push for disarmament, prompted by All Quiet on the Western Front and other reminders of the First World War, few countries make any serious moves. French and British demands for heavy war reparations, lead to Germany's economic ruin, but this and other unforseen consequences of the Treaty of Versailles would result in the emergence of Adolf Hitler. As Germany begins to absorb its neighbours, the rest of europe mobilises, and the moral utility of pacifism is questioned. The introductory scene shows Armistice Day. Interviewees include Lord Soper.

Henry Ford uses Taylorism, division of labour and the assembly line to manufacture automobiles, and other industries in the United States, as well as Britain, France, Italy, Soviet Union and elsewhere follow his example. The productivity dividends that are gained allow American workers to enjoy high pay and affordable consumer goods as compensation. However workers become increasingly frustrated from the physically demanding and alienating aspects of the assembly line (depicted in Modern Times, Brave New World and À nous la liberté). The Great Depression weakens worker bargaining power, but after a series of strikes in the 1930s and 1940s trade unions emerge victorious, and instruments like the Matignon Agreements in France are established to buttress workers' rights.

The cinema excites, inspires and influences people seeking escape from their usually dull lives. Hollywood booms in the 1920s, and its movies dominate European screens after the Second World War, bringing alluring images of America. Censorship is introduced after concerns are raised of cinema's perceived affect on morals. Television will however cut short cinema's future, in the west . Clips shown in this episode come from silent films (Salome, Raja Harishchandra, Cinderella, Son of the Sheik, Sherlock Jr. and Dr. Jekyll and Mr. Hyde), musicals (Achut Kanya, Sing As We Go, Flying Down to Rio, The Stars Shine, On the Town, Chandralekha and Mother India), propaganda films (Earth, The Sea Hawk; Know Your Enemy: Japan, The Fall of Berlin and Luciano Serra pilota), and films with allegorical messages (Les Visiteurs du Soir, Ladri di biciclette and Meet Mr. Lucifer). The introductory scene shows audience observing the first sound film, The Jazz Singer.

The Great Depression and its effects (and government counter-measures) in Britain, the United States, Sweden, Germany and Chile.

Once an amateur pursuit, sport becomes larger and more competitiveness to satisfy the public's need for excitement and identity. Communities unite behind favoured sporting clubs, as are entire countries that support their national teams against rivals. From the 1908 Olympics onwards, countries increasingly stake national pride on the successes of their athletes. Football, tennis, boxing and baseball attract millions of fans, and in turn are increasingly commercialised for a wider audience. Nazi Germany seeks to exploit the 1936 Berlin Olympics and the Joe Louis vs. Max Schmeling bouts for propaganda purposes, with mixed results. The introductory scene shows the 1930 FIFA World Cup, won by Uruguay against its arch-rival Argentina. Interviewees include Eddie Futch, Robert Mitchell, Helen Stephens and Fritz Schilgen.

The Third Reich brings barbarity to the modern era. Germany is rebuilt through huge public works program, winning Hitler adulation from a once humiliated, impoverished and unemployed German people. Radio and mass rallies become important tools for propaganda, to eulogise the Germans as a 'master race'. The Nazis also use ancient jealousies to demonise the Jews, who had a strong presence in the professions and arts. Roma, the mentally handicapped and other groups are also targeted. The Nuremburg Laws and other measures are used to progressively discriminate against and dehumanise Jews. Persecution of the Jews intensifies after Anschluss and Kristallnacht, and after the commencement of war, the Final Solution is implemented. The mass murder of Jews and other people is carried out at first by mobile killing groups (Einsatzgruppen) in occupied territories, and then on an industrialised scale through extermination camps. The introductory scene shows the celebratory march by the Sturmabteilung when Hitler wins power in Germany.

The Second World War enmeshes civilians to the horrors of war on an unprecedented scale. Germany and Japan, in seeking living space, kill and enslave entire populations in the Soviet Union and Asia respectively. Initially considered barbarous, people begin to accept as fair game the aerial bombing of civilian populations, and escalating calls for retaliation bring destruction to cities including Plymouth, Hamburg and Tokyo. Civilians are also in the front line in the Siege of Leningrad, but despite hardships, its orchestra manages to perform Shostakovich's Symphony No. 7. The mobilisation of civilians in the United States and elsewhere gives the allies quantitative superiority in the production of armaments, and ultimately victory. The introductory scene shows prescient footage of aerial bombing in the 1936 film Things to Come.

Nuclear weapons make the world more dangerous than ever before. The destruction of Hiroshima and Nagasaki in 1945 by atom bombs is hailed for ending the Second World War, but the long-term effects of radiation are discovered years later. To ensure parity with the US, Stalin puts his scientists to work and four years later the Soviet Union explodes its first nuclear bomb, starting an arms race between the superpowers in which peace is maintained through the doctrine of mutually assured destruction. Governments take steps to protect its citizens through civil defence. Popular movements calling for nuclear disarmament appear in force from the late 1950s, and the expensive arms race is eventually stopped in the 1980s. Nuclear power supports economic growth and technological advances, but the Chernobyl disaster in 1986, as well as the impact of nuclear testing in Utah and Bikini Atoll, keep the public at large distrustful of nuclear science. The opening scene shows the preparation and execution of the world's first nuclear test in New Mexico, United States.

Despite being allies against Hitler, disagreement and rivalry soon break out between the Soviet Union and the West, leading to the Cold War. The Soviet Union installs puppet regimes across Eastern Europe with planned economies, prompting Churchill to deliver his Iron Curtain speech. Both sides increasingly distrusts the other, and use propaganda to promote their cause. In 1949 McCarthyism and the Mosinee mock Soviet coup demonstrate US anxiety about communism following Soviet acquisition of the atom bomb and the victory of communism in China. The Berlin Blockade, the Korean War and the Hungarian Revolution of 1956 become flashpoints, although both sides eventually begin to believe in peaceful coexistance and accept a division of spheres of influence. The Soviet Block remains wary of the influence of Western ideas and its superior standard of living, and in 1962 reinforces its divide with the West by building the Berlin Wall. The introductory scene shows the fracternal relationship that had existed between Soviet and Western forces when they finally met in Germany in 1945. Interviewees include Manny Fried and Gail Halverson.

European powers are forced to relinquish their colonies in Africa following the Second World War, but in most cases the newly independent countries would eventually succumb to poverty, civil war and despotic regimes. India's independence motivates a generation of war veterans from Africa, who for the first time have travelled the world, to seek greater autonomy for their own countries. The Europeans are at first reluctant to surrender colonies that supports their prosperity, although Asia is decolonised in the 1950s. The British give reforms to the Gold Coast (now Ghana), which under Kwame Nkrumah would lead the way to independence, and ultimately become an example to the rest of Africa. Kenya's path to independence would not be without blood, and the British fight the Mau Mau to protect the numerically small white population. France and Portugal both struggle to keep their colonies. Within three years, 25 African states would become independent from their colonial masters, but tribal hatreds, corruption, a lack of a skilled workforce and internal conflict often lead these countries to ruin. The introductory scene shows India's path towards independence. Interviewees include Komla Gbedema and E. T. Mensah.

The rebuilding of Europe and the economic boom in the West, up to the 1973 oil shock.

Through thrift, hard work and discipline, Japan and later South Korea enjoy economic miracles that bring growth, prosperity and confidence to their once war-ravaged and impoverished people. In Japan the Korean War kickstarts manufacturing, and growth is sustained through export-orientated industries using Western technologies and production methods, and assisted by a dedicated, highly educated labour force strongly committed to improving their country. In the 1960s President Park Chung Hee largely followed Japan 's economic policies in steering South Korea's stellar economic development, but was far more ruthless to dissent and labour movements. The peoples of both countries eventually enjoy the consumer items as the fruits of their efforts, and their personal attitudes change as a result. The introductory scene shows the end of US occupation in Japan.

Medical advances allow people to live longer and healthier lives. Penicillin is developed in time to save lives during the Second World War. After the war national public health institutions are established, and national and international efforts are directed towards treatments against infectious diseases including typhus, tuberculosis and polio. Smallpox, the scourge of developing countries, is also eradicated. As deaths from infectious diseases are reduced, population booms in those developing countries with high birth rates – China and India take measures to promote family planning. Cholera becomes a risk in countries with insufficient sanitation to prevent water-borne diseases. AIDS spreads in Africa and elsewhere, and unlike other diseases appears untreatable. By the 1990s health in the developing world has much improved, and reduced infant mortality rates have lowered birth rates across the world. The introductory scene shows the United States in the 1950s when polio was prevailant.

Through non-violent and more direct methods, people rally to fight segregation in South Africa, and several states in the United States. In the United States state President Eisenhower uses federal troops to uphold the Constitutional rights of African American students during the Little Rock integration crisis. This action emboldens the civil rights movement to further confront Jim Crow laws through the sit-ins, the freedom rides,the March on Washington and the Selma to Montgomery marches. In South Africa from 1948 white supremacy is vigorously enforced through apartheid, pass laws, the Group Areas Act and other measures as well as other petty apartheid with legal recourse to protest denied. Incidents in Sharpeville and Soweto catalyse the grievences of Africans into direct action, forcing the Government to eventually negotiate with the ANC, free Nelson Mandela and hold South Africa's first democratic election in 1994.

Rising consumption patterns extract a huge toll on nature. Toxic contamination in Minamata and Love Canal and the Torrey Canyon and Amoco Cadiz oil slicks prompt public awareness about the planet's vulnerabilities, influenced by scientists including Rachel Carson and Paul Ehrlich. Following Earth Day in 1970 governments take resolute measures to mitigate pollution, such as through the Stockholm Conference as well as domestic measures like the Clean Air Act in the United States. Environmentalism emerges as a political force, championed by Greenpeace, Chipko and other organisations. In the 1980s new challenges emerge including global warming and acid rain, and the increasing size of industrial facilities make disasters like Bhopal and Chernobyl more deadly. Pressure was also being applied from newly developing countries. Interviewees include Lois Gibbs and Robert Hunter.

Governments, advertisers and revolutionaries seek to exploit television's ability to instantly communicate compelling messages to mass audiences. Television allows people to vividly witness Queen Elizabeth's Coronation, the 1960 US Presidential election, the moon landing, the Munich Olympics, the Tienanmen Square Massacre, the Romanian Revolution of 1989 and the Gulf War. Advertising, education programs, and series like Ramayan, Dallas and Oshin influence society by changing perceptions and habits. The introductory scene showed the impact of television in communicating the news of the assassination of President Kennedy. Interviewees include Abu Daoud and Don Hewitt.

Communism helps modernise China, but the decisions and personality cult of Mao Tse Tung has a traumatic affect on Chinese society. Mao's Chinese Communist Party defeats the Chinese nationalists after co-opting the support of China's peasantry. Driven by ideological furveor, the Chinese people are mobilised to develop the country, although many ill-considered initiatives like the Great sparrow campaign and the Great Leap Forward bring famine and chaos to China. Mao directs mass movements to attack what he perceived were disloyal or ideologically impure elements in China, in particular during the Cultural Revolution Order is only effectively restored to China following Mao's death in 1976, when Premier Deng Xiaopeng takes a more practical approach to ruling China. The introductory scene shows Mao proclaiming the People's Republic of China in Tienanmien Square in 1949.

The baby boom produced a cohort of children in the affluent and secure post-war world who for the first time would question established trends, culture and authority. Young adults were denied the right to vote, and lived in a paternalistic society that discouraged them from interacting with authority. Their rising disposable incomes were channelled into new music and fashions that helped provide them with a new common identity. Greater student populations, disillusionment with conformist trends, identification with civil rights issues and concern about the Vietnam War (where some youth were at risk of being drafted to) led to widespread protests in the West. A counterculture of drugs and hippies also emerged amongst the less engaged. Protests against authority emerges across the world with varying results – the May 1968 student uprising in France is curtailed by pragmatic workers not wishing to become involved, while crackdowns at the Chicago Convetion and Kent State University radicalise previously peaceful demonstrators in the United States. From the 1970s, following the end of US involvement in Vietnam, tighter employment conditions and the emergence of a more consultative culture in the West, youth find less reasons to protest.

Women struggle to win political and economic rights in societies gamed to entrench male privilege. Even with limited suffrage, after the First World War many Western women remain destined to a life of domestic servitude or limited careers. The Second World War gives women in Britain and the United States a brief opportunity to work in traditionally male industries, but they are promptly replaced at war's end. In the 1960s new household appliances, higher education and the book The Feminine Mystique inspires campaigns for equal pay and employment opportunities, such as the Dagenham strike. However women would still need to struggle against discrimination and harassment in male dominated careers. The pill helps women gain control of their fertility. In less developed of the world there are other issues of concern to women, including genital mutilation, dowry killings and infancide, while in Iran a legacy of gender equality is rolled back after the Islamic Revolution Fourth World Conference on Women shows how the aspirations and achievements for women vary between rihch and poor countries. The introductory scene shows the 1970 Women's Strike for Equality. Interviewees include Jacqui Ceballos and Mary Stott.

While in the second half of the century there are fewer conventional wars, civil conflicts under the backdrop of superpower rivalries emerge, fought by ideologically-driven guerilla movements. While usually being small and poorly armed, their motivation, self-belief and their abilities to co-opt popular support and exploit terrain to their own advantage prove to be key factors why several guerrila movmements are successful. With only a very small band of determined supporters, Fidel Castro manages to eventually overthrow Fulgencio Batista in the Cuban Revolution. After the French are defeated by the Viet Minh in Vietnam, the Americans deploy in huge numbers, however their technological prowess, industrial might and Hearts and Minds campaigns cannot defeat the Viet Cong. Similarly in Afghanistan, the Soviets are forced to pull out by the US-armed Mujahideen. The introductory scene shows the fall of Saigon. Interviewees include Ahmed Shah Masoud, General Vo Nguyen Giap and Colonel David Hackworth.

Religion makes a comeback into people's lives in the Islamic world and elsewhere, as people seek guidance and spiritual sustenance during periods of modernisation and social upheaval. Starting in Turkey under Atatürk, throughout the Islamic world governments introduce Western technology, fashion and culture to modernise and strengthen their countries. However public perceptions that commercialism and secularism are leading a breakdown in Islamic values galvanise Islamist movements in Egypt, Sudan, Pakistan and even Turkey. The greatest transformation of society takes place following the Islamic Revolution in Iran, where Sharia law, sex segregation and veils are (re)introduced, and similar measures are adopted elsewhere. Religious fundamentalism also surfaces in the United States, Israel and India. The introductory scene features the Shah of Iran showcasing his country in 1971, and his departure in 1979.

The end of communism in Europe and the fall of the Soviet Union. Opening credits show the fall of the Berlin Wall.

Governments around the world liberalise trade and withdraw from intervening in the economy, giving new opportunities to those who are skilled, industrious and adaptable, but disrupts the social order for others. In the United States, Proposition 13 is the precursor to Reaganism, and the inequalities that later emerge lead to the LA riots and the rise of gated communities. Russian society struggles to adapt to a market economy, and in Bosnia and elsewhere the demise of socialism revives ethnic tensions and separatism. However in China economic reforms started by Deng Xiaopeng lift living standards, and the internet allows high-skill work to be transferred from the West to India. The episode ends with the narrator noting how globalisation has contributed to one of the most significant achievements of the twentieth century – that more people have control over their own destinies than ever before. Interviewees include Donald Hodge and Mike Eruzione.