In the first episode of the series, Martin Geissler presents 'The World's Largest Refugee Camp - Four Years On'. In 2011, Martin Geissler visted the Dadaab Refugee Camp in Eastern Kenya. The camp's overcrowding population was due to people fleeing Al-Shabaab militants and the famine in Somalia. Martin returns to Dadaab to see what has changed. A few months ago Kenya threatened to close the camp, leaving large populations of people without anywhere to go - what now for the people of the Dadaab Refugee Camp? Alok Jha presents 'Nevada - Atomic Bomb'. The US government carried out 928 nuclear tests between 1951 and 1992 in a remote area known as the Nevada Test Site. Alok spoke to the surviving veterans and civilians who witnessed the atom bomb test first hand. Many people experienced the fall-out miles away in Utah and have been plagued with illnesses ever since. Alok asks: how do the veterans of the test site deal with their past pride in nuclear history with the horrendous effects of the fallout?Rageh Omaar presents 'Beirut - A Tale of Two Cities'. Beirut has for many decades been described as the Paris of the Middle East however it has also been associated with decades of civil war. Rageh Omaar travels to Beirut to find if there still fears amongst the city's different communities. Rageh questions whether the war in neighbouring Syria will crack Beirut's stability.